Novel polyquinoline derivatives and the therapeutic use thereof

ABSTRACT

The invention relates to a method for chelating metal ion and/or dissolving amyloid aggregates, including chelating metal ions and/or dissolving amyloid aggregates with a compound of formula (I):

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of copending application Ser. No.11/997,821 filed on Feb. 4, 2008; which is the 35 U.S.C. 371 nationalstage of International application PCT/FR2006/001906 filed on Aug. 4,2006; which claims priority to French application 0508351 filed on Aug.4, 2005. The entire contents of each of the above-identifiedapplications are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to novel polyquinoline derivatives, to theprocess for the preparation thereof and to the use thereof astherapeutic agents.

More precisely, compounds according to the present invention are metalligands and/or dissolve amyloid aggregates and are particularlyeffective in the treatment of neurodegenerative diseases.

DESCRIPTION OF THE RELATED ART

Various journals summarise data which demonstrates that many progressiveand slow neurodegenerative diseases are associated with: (i) anoxidative stress, (ii) protein misfolding leading to aggregate, fibril,profibril or plaque formation, (iii) an accumulation of these proteins,(iv) synapse loss, (v) homeostasis of the metal ions which have beenmodified, (vi) axonal and dendritic transport failure, (vii) neuraldeath. (E. Bossy-Wetzel et al., Nature Medecine, 2004, S2-S9 ; K. J.Barnham et al., Nature Rev. Drug Discov., 2004, 3, 205-214; M. P.Mattson, Nature, 2004, 430, 631-639; P. M. Doraiswamy et al., The LancetNeurol., 2004, 3, 431-434).

Many studies have recently demonstrated the fundamental role of metalions (copper, zinc, iron, aluminium, manganese, etc.) in themodification of protein folding and aggregation, leading to seriouspathologies. This destructive role of abnormal metal ion-proteininteraction has recently been emphasised in many neurodegenerativediseases, (for example: Alzheimer's disease, spongiformencephalopathies, Parkinson's disease, Huntington's disease, amyotrophiclateral sclerosis, etc.) or during the harmful development of somedisabilities, as in the case of Down syndrome. A specific protein orspecific proteins are associated with each disease, and it has beendemonstrated that metal ion chelating agents can be activated to reducetheir misfolding brought about by the metals.

In some encephalopathies, such as Creutzfeldt-Jakob's disease and itsnew variant, it is now acknowledged that these diseases are linked tothe transformation of a prion-type protein (PrP) in its pathological andinfectious form, known as “scrapie” (PrP^(sc)). Cupric ions are involvedin this conformational modification (beta-sheet formation) of theprions, which acquire protease resistance and become insoluble innon-denaturant detergents. Recent works have shown that a ligand such asbathocuproine disulfate can restore in vitro “scrapie” protein PrP^(sc)protease sensitivity and the solubility thereof (E. Quaglio et al., J.Biol. Chem., 2001, 276, 11432-11438).

In the case of Parkinson's disease, the α-synuclein interacts withferric ions. It has been suggested that these ions facilitate hydroxylradical formation, in particular oxidising hydroxyl radical formation,and studies using MRI post mortem have shown high concentrations offerric ions in patients' substancia nigra (a region of the brain wheredopaminergic neurones are more selectively affected in this disease).Use of chelators such as Clioquinol reduces the toxicity of1-methyl-4-phenyl-1,2,3,6-tetrapyridine, a toxin which causesParkinson's disease, in mice (D. Kaur et al., Neuron 2003, 37, 899-909).

In the case of Alzheimer's disease (M. P. Mattson, Nature, 2004, 430,631-639; M. Citron, Nature Rev. Neurosci., 2004, 5, 677-685), thepathology is linked to aggregation, in the brain, of β-amyloid peptides,leading to amyloid plaque formation. This aggregation may be induced byCu(II) and Zn(II)ions and, to a lesser extent, by Fe(III) ions.Accumulation within these redox-active metal ion plaques is likely tocause significant oxidative stress (via H₂O₂ production), itselfdamaging the neurones in the brain, leading to an irreversible loss ofintellectual abilities (M. P. Cuajungco et al., Ann. N.Y. Acad. Sci.,2000, 920, 292-304; C. S. Atwood et al., Met. Ions Biol. Syst., 1999,36, 309-364). The fact that the first tests to be carried out using ametal ion ligand such as Clioquinol led to improvements in Alzheimer'sdisease (R. A. Cherny et al., Neuron, 2001, 30, 665-676) indicates thattherapeutic approaches using metal ion chelators are possible.

However, these chelators must have the following properties to be ableto be used as drugs in the treatment of neurodegenerative diseases:

-   -   (a) have a low molecular weight and not be too highly charged in        order to be able to cross the various barriers (firstly,        intestinal, in the case of a molecule taken orally and then, in        a reversible manner, the blood-brain barrier for chelating the        metal ions present in excess in the pathogenic proteins),    -   (b) have a modifiable structure in order to adjust chelation        selectivity to specific metal ions (a strong, non-specific        chelation would result in a general depletion of metal ions,        including those of metalloenzymes, which are essential to the        functioning of the organism) or to make it possible to modulate        the biodistribution thereof in the organism.

Chelators with a quinoline unit substituted in position 8 by aheteroatom (such as 8-hydroxyquinoline derivatives, for example) arecandidates for chelating the excess metal ions involved in theneurodegenerative diseases. This type of ligand is expected often toform copper, zinc or iron complexes (metal ions associated with proteinaggregation and even oxidative stress, with regard to copper and iron),comprising two (and even three in the case of iron) ligands around themetal ion (Sillen, L. G. et al., Stability Constants of Metal-IonComplexes, The Chemical Society London Publication, 1971).

Bis-quinoline derivatives have been described, but rarely as agents forthe treatment of potential diseases of the nervous system. WO2004/007461 thus describes the property of a metal chelator. However,this document basically describes mono-quinoline compounds. Furthermore,EP 0 443 862 describes NMDA receptor agonist derivatives, and in no waysuggests metal chelator activity of the described compounds. Finally,Stockwell et al. in J. Am. Chem. Soc. 1999, 10662-10663 describe thebiological activity of the compounds 2,2′-(imino)bis(8-quinolinol) andits derivatives 2,2′-(methylimino)- and2,2′-(n-butylimino)-bis(8-quinolinol).

SUMMARY OF THE INVENTION

It has now surprisingly been found that the 2,2′- or 8,8′-poly-quinolinecompounds according to the invention have a strong metal-chelatingactivity and/or are able to dissolve amyloid aggregates.

The term “amyloid aggregates” denotes a polymeric structure of Aβpeptides generated by secondary, tertiary or quaternary interaction (ofsheet β, for example) or by biometallic coordination on the peptide (E.Scarpini et al., The Lancet Neurology, 2003, 2, 539-547; E. Gaggeli etal., Chem. Rev., 2006, 106, 1995-2044; A. B. Clippingdale et al., J.Peptide Sc., 2001, 7, 227-249).

These compounds are useful as drugs for the treatment and/or preventionof neurodegenerative diseases, in particular Alzheimer's disease,Parkinson's disease, spongiform encephalopathies, Huntington's disease,amyothrophic lateral sclerosis or Down syndrome.

The present inventors have thus developed chelators comprising aplurality of small substituted quinoline units (in position 2 or 8)which are sufficiently hydrophobic to be able to cross barriers. Theyhave thus demostrated that these structures aid interaction of moleculeheterocycles on the same metal ion and that substitutions on theseligands, which have been introduced in a controlled manner, can modulatethe action thereof with respect to proteins involved inneurodegenerative diseases: properties of chelation, in particular ofCu(II), Zn(II) and Fe(III) ions involved in these diseases, ofhydrophobicity, of the capacity to disaggregate proteins involved inneurodegenerative diseases whether or not in the presence of metal ion,or of decreasing the oxidative stress that they can induce.

BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to the use of compounds of formula (I)

for the preparation of pharmaceutical compositions for chelating metalions and/or dissolving amyloid aggregates

wherein in formula (I)

either

X represents an —OR, —NRR′, —S(O)_(p)R, —OCOR or —OCOOR group, and

Y represents a group of formula:

in which X′ represents an —OR, —NRR′, —S(O)_(p)R, —OCOR or —OCOOR groupand Z represents a group of formula-(A)_(m)-(Alk)_(n)-(A′)_(m′)-(Alk′)_(n′)-(A″)_(m″)-(Alk″)_(n″), where m,n, m′, n′, m″ and n″ are the same or different and independentlyrepresent 0 or 1, it being understood that at least one of m, n, m′, n′m″ and n″ is equal to 1, A, A′ and A″ are the same or different andindependently represent a group selected from —NR—, —S(O)p-, —O— and—C(═O)—, or a 4-11 membered ring selected from cycloalkyls,heterocycles, aryls and heteroaryls, said ring being optionallysubstituted by one or more substituents selected from alkyl, OR, NRR′,CF₃, Hal, CN, S(O)_(p)R, COOR, OCOOR, CONRR′ and NRCOOR′;

Alk, Alk′ and Alk″ are the same or different and independently representan -alkyl- group optionally substituted by one or more substituentsselected from OR, NRR′, CF₃, Hal, CN, S(O)_(p)R, COOR, OCOOR, CONRR′ andNRCOOR′;

or

X represents a group of formula:

in which Z represents a group of formula-(A)_(m)-(Alk)_(n)-(A′)_(m′)-(Alk′)_(n′)-(A″)_(m″)-(Alk″)_(n″), where m,n, m′, n′, m″ and n″ are the same or different and independentlyrepresent 0 or 1, it being understood that at least one of m, n, m′, n′m″ and n″ is equal to 1,

A, A′ and A″ are the same or different and independently represent agroup selected from —NR—, —S(O)p-, —O— and —C(═O)—, or a 4-11 memberedring selected from cycloalkyls, heterocycles, aryls and heteroaryls,said ring being optionally substituted by one or more substituentsselected from alkyl, OR, NRR′, CF₃, Hal, CN, S(O)_(p)R, COOR, OCOOR,CONRR′ and NRCOOR′;

-   Alk, Alk′ and Alk″ are the same or different and independently    represent an -alkyl- group, optionally substituted by one or more    substituents selected from OR, NRR′, CF₃, Hal, CN, S(O)_(p)R, COOR,    OCOOR, CONRR′ and NRCOOR′;

Y represents a group selected from H, OR, NRR′, Hal, —CN, —CF₃ and alkyloptionally substitued by one or more substituents selected from OR,NRR′, CF₃, Hal, CN, S(O)_(p)R, COOR, OCOOR, CONRR′ and NRCOOR′;

and

R and R′ are the same or different and independently represent ahydrogen atom or a cycloalkyl or alkyl group optionally substituted byone or more groups selected from OR, NRR′, Hal, —CN, —CF₃, S(O)_(p)R,COOR, OCOOR, CONRR′ and NRCOOR′; heteroaryl;

R1, R2, R3, R4, R5, R1′, R2′, R3, R4′, R5′ and R6′ are the same ordifferent and independently represent a group or atom selected from H,OR, NRR′, Hal, —CN, —CF₃, S(O)_(p)R, COOR, OCOOR, CONRR′, NRCOOR′ andalkyl optionally substituted by one or more groups selected from OR,NRR′, Hal, —CN, —CF₃, S(O)_(p)R, COOR, OCOOR, CONRR′ and NRCOOR′;

k represents 1 or 2;

p represents 0, 1 or 2;

as well as the pharmaceutically acceptable stereoisomers or mixtures,tautomeric forms, hydrates, solvates, salts, free forms and estersthereof,

with the exception of compounds for which:

X represents an —OH group, and

Y represents a group of formula:

in which X′ represents an —OH group, and

Z represents a group selected from —NH—, —NBu-, —NMe-, and

R1, R2, R3, R4, R5, R1′, R2′, R3′, R4′, R5′ and R6′ are equal to H.

More preferably, compounds for the present use are selected from:

dimethyl-bis[8-(acetyloxy)-2-quinoline]propanedioate

2,2′-methanediyl-bis(8-hydroxyquinoline)

2,2′-methanediyl-bis(5-chloro-8-hydroxyquinoline)

2,2′-(2,2-propanediyl)-bis(8-hydroxyquinoline)

2,2′-(2,2-propanediyl)-bis(5-chloro-8-hydroxyquinoline)

2,2′-(difluoromethanediyl)-bis(8-hydroxyquinoline)

bis(8-hydroxy-2-quinolinyl)methanone

2,2′-(1,2-ethanediyl)-bis[8-(methyloxy)quinoline]

2,2′-(1,2-ethanediyl)-bis(8-hydroxyquinoline)

2,2′-(1,2-ethanediyl)-bis(5-chloro-8-hydroxyquinoline)

2,2′-(1,2-ethanediyl)-bis(5-chloro-7-iodo-8-hydroxyquinoline)

2,2′-(1,4-butanediyl)-bis[8-(methyloxy)quinoline]

2,2′-(1,4-butanediyl)-bis(8-hydroxyquinoline)

2,2′,2″-(1,2,3-propanetriol)-tris[8-(methyloxy)quinoline]

2,2′,2″-(1,2,3-propanetriol)-tris(8-hydroxyquinoline)

bis(8-quinolinyl)amine

N,N′-di-8-quinolinyl-1,3-propanediamine

8,8′-oxydiquinoline

N,N′-bis(2-methyl-8-quinolinyl)-1,2-ethanediamine

dimethylbis{7-(methyloxy)8-[phenylmethyl)oxy]-2-quinolinyl}propanedioate

2,2′-(methanediyl)-bis(7-methyloxy-8-hydroxy-2-quinolinium) dichloride

2,2′-(1,2-ethanediyl)-bis[7-(methyloxy)-8-quinolinol]

8-hydroxy-N-(8-hydroxy-2-quinolinyI)-2-quinoline carboxamide

2-{[8-hydroxy-2-quinolinyl)amino]methyl}-8-quinolinol

2,2′-(iminodimethanediyl)di(N-boc-8-quinoline amine)

2,2′-(Iminodimethanediyl)di(8-quinoline amine)

2,2′,2″-(nitrilotrimethanediyl)tri(N-boc-8-quinoline amine)

2,2′,2″-(nitrilotrimethanediyl)tri(8-quinoline amine)

2,2′-[(butylimino)dimethanediyl]di(N-boc-8-quinoline amine)

2,2′-[(butylimino)dimethanediyl]di(8-quinoline amine)

N-butyl-2,2′-imino-bis(8-quinoline amine)

N-8-quinolinyl-8-quinoline carboxamide

N-8-quinolinyl-8-quinoline sulfonamide

as well as the pharmaceutically acceptable stereoisomers or mixtures,tautomeric forms, hydrates, solvates, salts, free forms and estersthereof.

According to another subject-matter, the present invention also relatesto use of compounds of formula (I)

for the preparation of pharmaceutical compositions for preventing and/ortreating diseases affecting the central nevrvous system, such asneurodegenerative

diseases

wherein in formula (I):

either

X represents an —OR, —NRR′, —S(O)_(p)R, —OCOR or —OCOOR group and

Y represents a group of formula:

in which X′ represents an —OR, —NRR′, —S(O)_(p)R, —OCOR or —OCOOR groupand Z represents a group of formula-(A)_(m)-(Alk)_(n)-(A′)_(m′)-(Alk′)_(n′)-(A″)_(m″)-(Alk″)_(n″), where m,n, m′, n′, m″ and n″ are the same or different and independentlyrepresent 0 or 1, it being understood that at least one of m, n, m′, n′m″ and n″ is equal to 1, A, A′ and A″ are the same or different andindependently represent a group selected from —NR—, —S(O)p-, —O— and—C(═O)—, or a 4-11 membered ring selected from cycloalkyls,heterocycles, aryls and heteroaryls, said ring being optionallysubstituted by one or more substituents selected from alkyl, OR, NRR′,CF₃, Hal, CN, S(O)_(p)R, COOR, OCOOR, CONRR′ and NRCOOR′;

Alk, Alk′ and Alk″ are the same or different and independently representan -alkyl- group, optionally substitued by one or more substituentsselected from OR, NRR′, CF₃, Hal, CN, S(O)_(p)R, COOR, OCOOR, CONRR′ andNRCOOR′;

or

X represents a group of formula:

in which Z represents a group of formula-(A)_(m)-(Alk)_(n)-(A′)_(m′)-(Alk′)_(n′)-(A″)_(m″)-(Alk″)_(n″) where m,n, m′, n′, m″ and n″ are the same or different and independentlyrepresent 0 or 1, it being understood that at least one of m, n, m′, n′m″ and n″ is equal to 1,

A, A′ and A″ are the same or different and independently represent agroup selected from —NR—, —S(O)p-, —O— and —C(═O)—, or a 4-11 memberedring selected from cycloalkyls, heterocycles, aryls and heteroaryls,said ring being optionally substituted by one or more substituentsselected from alkyl, OR, NRR′, CF₃, Hal, CN, S(O)_(p)R, COOR, OCOOR,CONRR′ and NRCOOR′;

Alk, Alk′ and Alk″ are the same or different and independently representan -alkyl- group, optionally substituted by one or more substituentsselected from OR, NRR′, CF₃, Hal, CN, S(O)_(p)R, COOR, OCOOR, CONRR′ andNRCOOR′;

Y represents a group selected from H, OR, NRR′, Hal, —CN, —CF₃ and alkyloptionally substitued by one or more substituents selected from OR,NRR′, CF₃, Hal, CN, S(O)_(p)R, COOR, OCOOR, CONRR′ and NRCOOR′;

and

R and R′ are the same or different and independently represent ahydrogen atom or a cycloalkyl or alkyl group, optionally substituted byone or more groups selected from OR, NRR′, Hal, —CN, —CF₃, S(O)_(p)R,COOR, OCOOR, CONRR′ and NRCOOR′; heteroaryl;

R1, R2, R3, R4, R5, R1′, R2′, R3, R4′, R5′ and R6′ are the same ordifferent and independently represent a group or atom selected from H,OR, NRR′, Hal, —CN, —CF₃, S(O)_(p)R, COOR, OCOOR, CONRR′, NRCOOR′, andalkyl optionally substituted by one or more substituents selected fromOR, NRR′, CF₃, Hal, CN, S(O)_(p)R, COOR, OCOOR, CONRR′ and NRCOOR′;

k represents 1 or 2;

p represents 0, 1 or 2;

as well as the pharmaceutically acceptable stereoisomers or mixtures,tautomeric forms, hydrates, solvates, salts, free forms and estersthereof,

with the exception of compounds for which:

X represents an —OH group, and

Y represents a group of formula:

in which X′ represents an —OH group,

Z represents a group selected from —NBu-, —NMe-, and

R1, R2, R3, R4, R5, R1′, R2′, R3′, R4′, R5′ and R6′ are equal to H andcompounds for which

X represents a group of formula:

in which Z represents a group of formula —(NH)—(CH₂)₂—(NH)—(CH₂)₂—(NH)—,

Y represents H

R1, R2, R3, R4, R5, R1′, R2′, R3′, R4′, R5′ and R6′ represent H.

More preferably, compounds for the present use according to theinvention are selected from:

dimethyl-bis[8-(acetyloxy)-2-quinoline]propanedioate

2,2′-methanediyl-bis(8-hydroxyquinoline)

2,2′-methanediyl-bis(5-chloro-8-hydroxyquinoline)

2,2′-(2,2-propanediyl)-bis(8-hydroxyquinoline)

2,2′-(2,2-propanediyl)-bis(5-chloro-8-hydroxyquinoline)

2,2′-(difluoromethanediyl)-bis(8-hydroxyquinoline)

bis(8-hydroxy-2-quinolinyl)methanone

2,2′-(1,2-ethanediyl)-bis[8-(methyloxy)quinoline]

2,2′-(1,2-ethanediyl)-bis(8-hydroxyquinoline)

2,2′-(1,2-ethanediyl)-bis(5-chloro-8-hydroxyquinoline)

2,2′-(1,2-ethanediyl)-bis(5-chloro-7-iodo-8-hydroxyquinoline)

2,2′-(1,4-butanediyl)-bis[8-(methyloxy)quinoline]

2,2′-(1,4-butanediyl)-bis(8-hydroxyquinoline)

2,2′,2″-(1,2,3-propanetriol)-tris[8-(methyloxy)quinoline]

2,2′,2″-(1,2,3-propanetriol)-tris(8-hydroxyquinoline)

bis(8-quinolinyl)amine

N,N′-di-8-quinolinyl-1,3-propanediamine

8,8′-oxydiquinoline

N,N′-bis(2-methyl-8-quinolinyl)-1,2-ethanediamine

dimethylbis{7-(methyloxy)8-[phenylmethyl)oxy]-2-quinolinyl}propanedioate

2,2′-(methanediyl)-bis(7-methyloxy-8-hydroxy-2-quinolinium) dichloride

2,2′-(1,2-ethanediyl)-bis[7-(methyloxy)-8-quinolinol]

8-hydroxy-N-(8-hydroxy-2-quinolinyl)-2-quinoline carboxamide

2-{[8-hydroxy-2-quinolinyl)amino]methyl}-8-quinolinol

2,2′-(iminodimethanediyl)di(N-boc-8-quinoline amine)

2,2′-(iminodimethanediyl)di(8-quinoline amine)

2,2′,2″-(nitrilotrimethanediyl)tri(N-boc-8-quinoline amine)

2,2′,2″-(nitrilotrimethanediyl)tri(8-quinoline amine)

2,2′-[(butylimino)dimethanediyl]di(N-boc-8-quinoline amine)

2,2′-[(butylimino)dimethanediyl]di(8-quinoline amine)

N-butyl-2,2′-imino-bis(8-quinoline amine)

N-8-quinolinyl-8-quinoline carboxamide

N-8-quinolinyl-8-quinoline sulfonamide

as well as the pharmaceutically acceptable stereoisomers or mixtures,tautomeric forms, hydrates, solvates, salts, free forms and estersthereof.

In particular, the invention relates to a use, wherein the compound isselected from bis(8-quinolinyl)amine and2,2′-(2,2-propanediyl)-bis-(8-hydroxyquinoline), these compounds havingno mutagenic or bactericidal effect, in particular according to theadapted Ames test of D. M. Maron and B. N. Ames, Mutat. Res. 1983, 113,173-215; D. E. Levin et al., Mutat. Res. 1982, 94, 315-330; D. E. Levinet al. Proc. Natl. USA 1982, 79, 7445-7449, in particular on TA98 and/orTA100 Salmonella strains in the absence or presence of enzymatichomogenate (S9) of rat liver microsomes.

According to another subject-matter, the present application relates topharmaceutical compositions comprising a compound of formula (I)

wherein in formula (I)

X represents an —OR, —NRR′, —S(O)_(p)R or —OCOOR group and

Y represents a group of formula:

in which X′ represents an —OR, —NRR′, S(O)_(p)R, —OCOOR group and Zrepresents a group of formula-(A)_(m)-(Alk)_(n)-(A′)_(m′)-(Alk′)_(n′)-(A″)_(m″)-(Alk″)_(n″), where m,n, m′, n′, m″ and n″ are the same or different and independentlyrepresent 0 or 1, it being understood that at least one of m, n, m′, n′m″ and n″ is equal to 1, A, A′ and A″ are the same or different andindependently represent a group selected from —NR—, —S(O)p-, —O— and—C(═O)—, or a 4-11 membered ring selected from cycloalkyls,heterocycles, aryls and heteroaryls, said ring being optionallysubstituted by one or more substituents selected from alkyl, OR, NRR′,CF₃, Hal, CN, S(O)_(p)R, COOR, OCOOR, CONRR′ and NRCOOR′;

Alk, Alk′ and Alk″ are the same or different and independently representan -alkyl- group, optionally substituted by one or more substituentsselected from OR, NRR′, CF₃, Hal, CN, S(O)_(p)R, COOR, OCOOR, CONRR′ andNRCOOR′;

and

R and R′ are the same or different and independently represent ahydrogen atom or a cycloalkyl or alkyl group, optionally substituted byone or more groups selected from OR, NRR′, Hal, —CN, —CF₃, S(O)_(p)R,COOR, OCOOR, CONRR′ and NRCOOR′; heteroaryl;

R1, R2, R3, R4, R5, R1′, R2′, R3, R4′, R5′ and R6′ are the same ordifferent and independently represent a group or atom selected from H,OR, NRR′, Hal, —CN, —CF₃ and alkyl optionally substituted by one or moresubstituents selected from OR, NRR′, CF₃, Hal, CN, S(O)_(p)R, COOR,OCOOR, CONRR′ and NRCOOR′;

k represents 1 or 2;

p represents 0, 1 or 2;

as well as the pharmaceutically acceptable stereoisomers or mixtures,tautomeric forms, hydrates, solvates, salts, free forms and estersthereof,

with the exception of compounds for which:

X represents an —OH group, and

Y represents a group of formula:

in which X′ represents an —OH group, and

Z represents a group selected from —NH—, —NBu-, —NMe-,

R1, R2, R3, R4, R5, R1′, R2′, R3′, R4′, R5′ and R6′ are equal to H.

More preferably, compounds for pharmaceutical compositions according tothe invention are selected from:

dimethyl-bis[8-(acetyloxy)-2-quinoline]propanedioate

2,2′-methanediyl-bis(8-hydroxyquinoline)

2,2′-methanediyl-bis(5-chloro-8-hydroxyquinoline)

2,2′-(2,2-propanediyl)-bis(8-hydroxyquinoline)

2,2′-(2,2-propanediyl)-bis(5-chloro-8-hydroxyquinoline)

2,2′-(difluoromethanediyl)-bis(8-hydroxyquinoline)

bis(8-hydroxy-2-quinolinyl)methanone

2,2′-(1,2-ethanediyl)-bis[8-(methyloxy)quinoline]

2,2′-(1,2-ethanediyl)-bis(8-hydroxyquinoline)

2,2′-(1,2-ethanediyl)-bis(5-chloro-8-hydroxyquinoline)

2,2′-(1,2-ethanediyl)-bis(5-chloro-7-iodo-8-hydroxyquinoline)

2,2′-(1,4-butanediyl)-bis[8-(methyloxy)quinoline]

2,2′-(1,4-butanediyl)-bis(8-hydroxyquinoline)

2,2′,2″-(1,2,3-propanetriol)-tris[8-(methyloxy)quinoline]

2,2′,2″-(1,2,3-propanetriol)-tris(8-hydroxyquinoline)

dimethylbis{7-(methyloxy)8-[phenylmethyl)oxy]-2-quinolinyl}propanedioate

2,2′-(methanediyl)-bis(7-methyloxy-8-hydroxyquinolinium) dichloride

2,2′-(1,2-ethanediyl)-bis[7-(methyloxy)-8-quinolinol]

8-hydroxy-N-(8-hydroxy-2-quinolinyl)-2-quinoline carboxamide

2-{[8-hydroxy-2-quinolinyl)amino]methyl}-8-quinolinol

2,2′-(iminodimethanediyl)di(N-boc-8-quinoline amine)

2,2′-(iminodimethanediyl)di(8-quinoline amine)

2,2′,2″-(nitrilotrimethanediyl)tri(N-boc-8-quinoline amine)

2,2′,2″-(nitrilotrimethanediyl)tri(8-quinoline amine)

2,2′-[(butylimino)dimethanediyl]di(N-boc-8-quinoline amine)

2,2′-[(butylimino)dimethanediyl]di(8-quinoline amine)

N-butyl-2,2′-imino-bis(8-quinoline amine)

as well as the pharmaceutically acceptable stereoisomers or mixtures,tautomeric forms, hydrates, solvates, salts, free forms and estersthereof.

According to another subject-matter, the present invention relates tothe compounds of formula (I):

wherein in formula (I)

X represents an —OR, —NRR′, —S(O)_(p)R, —OCOOR or —NO₂ group and

Y represents a group of formula:

in which X′ represents an —OR, —NRR′, —S(O)_(p)R, —OCOOR or —NO₂ groupand Z represents a group of formula-(A)_(m)-(Alk)_(n)-(A′)_(m′)-(Alk′)_(n′)-(A″)_(m″)-(Alk″)_(n″), where m,n, m′, n′, m″ and n″ are the same or different and independentlyrepresent 0 or 1, it being understood that at least one of m, n, m′, n′m″ and n″ is equal to 1, A, A′ and A″ are the same or different andindependently represent a group selected from —NR—, —S(O)p-, —O— and—C(═O)—, or a 4-11 membered ring selected from cycloalkyls,heterocycles, aryls and heteroaryls, said ring being optionallysubstituted by one or more substituents selected from alkyl, OR, NRR′,CF₃, Hal, CN, S(O)_(p)R, COOR, OCOOR, CONRR′ and NRCOOR′;

Alk, Alk′ and Alk″ are the same or different and independently representan -alkyl- group optionally substitued by one or more substituentsselected from OR, NRR′, CF₃, Hal, CN, S(O)_(p)R, COOR, OCOOR, CONRR′ andNRCOOR′; and

R and R′ are the same or different and independently represent ahydrogen atom or a cycloalkyl or alkyl group, optionally substituted byone or more groups selected from OR, NRR′, Hal, —CN, —CF₃, S(O)_(p)R,COOR, OCOOR, CONRR′ and NRCOOR′; heteroaryl;

R1, R2, R3, R4, R5, R1′, R2′, R3, R4′, R5′ and R6′ are the same ordifferent and independently represent a group or atom selected from H,OR, NRR′, Hal, —CN, —CF₃ and alkyl optionally substituted by one or moresubstituents selected from OR, NRR′, CF₃, Hal, CN, S(O)_(p)R, COOR,OCOOR, CONRR′ and NRCOOR′;

k represents 1 or 2;

p represents 0, 1 or 2;

as well as the pharmaceutically acceptable stereoisomers or mixtures,tautomeric forms, hydrates, solvates, salts, free forms and estersthereof,

with the exception of compounds for which:

X represents an —OH group, and

Y represents a group of formula:

in which X′ represents an —OH group, and

Z represents a group selected from —CH₂—, —CH₂—CH₂—, —(CH₂)₆—, —CH═CH—,—C(Me)₂-, -thienyl-, —CH₂—S—CH₂—, —NH—, —NBu-, —NMe-, R1, R2, R3, R4,R5, R1′, R2′, R3′, R4′, R5′ and R6′ are equal to H.

More preferably, compounds according to the present invention areselected from:

2,2′-methanediyl-bis(5-chloro-8-hydroxyquinoline)

2,2′-(2,2-propanediyl)-bis(5-chloro-8-hydroxyquinoline)

2,2′-(difluoromethanediyl)-bis(8-hydroxyquinoline)

bis(8-hydroxy-2-quinolinyl)methanone

2,2′-(1,2-ethanediyl)-bis(5-chloro-8-hydroxyquinoline)

2,2′-(1,2-ethanediyl)-bis(5-chloro-7-iodo-8-hydroxyquinoline)

2,2′-(1,4-butanediyl)-bis[8-(methyloxy)quinoline]

2,2′-(1,4-butanediyl)-bis(8-hydroxyquinoline)

2,2′,2″-(1,2,3-propanetriol)-tris[8-(methyloxy)quinoline]

2,2′,2″-(1,2,3-propanetriol)-tris(8-hydroxyquinoline)

dimethylbis{7-(methyloxy)8-[phenylmethyl)oxy]-2-quinolinyl}propanedioate

2,2′-(methanediyl)-bis(7-methyloxy-8-hydroxy-2-quinolinium) dichloride

2,2′-(1,2-ethanediyl)-bis[7-(methyloxy)-8-quinolinol]

8-hydroxy-N-(8-hydroxy-2-quinolinyl)-2-quinoline carboxamide

2-{[8-hydroxy-2-quinolinyl)amino]methyl}-8-quinolinol

2,2′-(iminodimethanediyl)di(N-boc-8-quinoline amine)

2,2′-(iminodimethanediyl)di(8-quinoline amine)

2,2′,2″-(nitrilotrimethanediyl)tri(N-boc-8-quinoline amine)

2,2′,2″-(nitrilotrimethanediyl)tri(8-quinoline amine)

2,2′-[(butylimino)dimethanediyl]di(N-boc-8-quinoline amine)

2,2′-[(butylimino)dimethanediyl]di(8-quinoline amine)

N-butyl-2,2′-imino-bis(8-quinoline amine)

N-butyl-2,2′-imino-bis(8-quinoline amine)

as well as the pharmaceutically acceptable stereoisomers or mixtures,tautomeric forms, hydrates, solvates, salts, free forms and estersthereof.

Preferably, X represents OR and Y represents a group of formula (IY), inwhich X′ represents OR and Z represents A, where A represents —C(O)— orZ represents Alk, where Alk represents a linear or branched alkyl groupoptionally substituted by one or more halogen atoms; or

X represents OR and Y represents a group of formula (IY), in which X′represents OR and Z represents A-A′, where A represents —C(O)— and A′represents NR′; or

X represents OR and Y represents a group of formula (IY), in which X′represents OR and Z represents A-Alk, where A represents NR′ and Alkrepresents a linear or branched alkyl group optionally substituted byone or more halogen atoms; or

X represents NRR′ and Y represents a group of formula (IY), in which X′represents NRR′ and Z represents Alk-NR″-Alk, where Alk represents alinear or branched alkyl group optionally substituted by one or morehalogen atoms; or

X represents NRR′ and Y represents a group of formula (IY), in which X′represents NRR′ and Z represents NR″; or

X represents a group of formula (IX), in which Z represents —NR—,—NR-Alk-NR—, —O—, —NR—C(O)− or—NR—S(O)₂— and Y represents H;

k=1 or 2

R═H or COOR′ or alkyl, optionally substituted, R′=H or alkyl, optionallysubstituted, R″=H, alkyl or heteroaryl, optionally substituted, and

R1, R2, R3, R4, R5, R1′, R2′, R3, R4′, R5′ and R6′ are the same ordifferent and independently represents a group or atom selected from H,OR, NRR′, Hal, —CN, —CF₃, and alkyl optionally substituted by one ormore substituents selected from OR, NRR′, CF₃, Hal, CN, S(O)_(p)R, COOR,OCOOR, CONRR′ and NRCOOR′ as well as the pharmaceutically acceptablestereoisomers or mixtures, tautomeric forms, hydrates, solvates, salts,free forms and esters thereof.

Hereinbefore and hereinafter, it is understood in the definition of m,m′, m″, n, n′ and n″ that if m=m′=1 or m′=m″=1 or m=m′=m″=1 or m=m″=1and m′=0, then n=1 or n′=1 or n=n′=1 or at least n or n′=1 respectively.

According to the present invention, the alkyl radicals are straightchain or branched saturated hydrocarbon radicals, containing from 1 to20 carbon atoms, preferably from 1 to 5 carbon atoms.

The methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, nonyl, decyl,dodecyl, hexadecyl and octadecyl radicals can be mentioned in particularas linear radicals.

The isopropyl, tert-butyl, 2-ethylhexyl, 2-methylbutyl, 2-methylpentyl,1-methylpentyl and 3-methylheptyl radicals can be mentioned inparticular as branched radicals or radicals substituted by one or morealkyl radicals.

Alkoxy radicals according to the present invention are radicals offormula —O-alkyl, the alkyl being as defined hereinbefore.

Fluorine, chlorine, bromine and iodine atoms are mentioned in particularas halogen atoms

The alkenyl radicals are straight chain or linear hydrocarbon radicals,and comprise one or more ethylenically unsaturated bonds. Suitablealkenyl radicals include, in particular the allyl or vinyl radicals.

The alkynyl radicals are straight chain or linear hydrocarbon radicals,and comprise one or more acetylenically unsaturated bonds. Suitablealkynyl radicals, include, in particular, acetylene.

The cycloalkyl radical is a non-aromatic, saturated or partiallyunsaturated monocyclic, bicyclic or tricyclic hydrocarbon radicalcontaining from 3 to 11 carbon atoms, such as, in particular,cyclopropyl, cyclopentyl, cyclohexyl or adamantyl, as well as thecorresponding rings containing one or more unsaturated bonds.

The term “aryl” denotes a monocyclic or bicyclic hydrocarbon aromaticsystem containing from 4 to 11 carbon atoms.

Suitable aryl radicals include in particular the phenyl or naphthylradical, more particularly substituted by at least one halogen atom.

Suitable alkylaryl radicals include in particular the benzyl orphenethyl radical.

Heteroaryl radicals denote aromatic systems comprising one or moreheteroatoms selected from nitrogen, oxygen or sulphur, mono- orbicyclic, which contain from 4 to 11 carbon atoms. Suitable heteroarylradicals include pyrazinyl, thienyl, oxazolyl, furazanyl, pyrrolyl,1,2,4-thiadiazolyl, naphthyridinyl, pyridazinyl, quinoxalinyl,phthalazinyl, imidazo[1,2-a]pyridine, imidazo[2,1-b]thiazolyl,cinnolinyl, triazinyl, benzofurazanyl, azaindolyl, benzimidazolyl,benzothienyl, thienopyridyl, thienopyrimidinyl, pyrrolopyridyl,imidazopyridyl, benzoazaindole, 1,2,4-triazinyl, benzothiazolyl,furanyl, imidazolyl, indolyl, triazolyl, tetrazolyl, indolizinyl,isoxazolyl, isoquinolinyl, isothiazolyl, oxadiazolyl, pyrazinyl,pyridazinyl, pyrazolyl, pyridyl, pyrimidinyl, purinyl, quinazolinyl,quinolinyl, isoquinolinyl, 1,3,4-thiadiazolyl, thiazolyl, triazinyl,isothiazolonyl, or carbazolyl, as well as the corresponding groupsresulting from fusion thereof or fusion with the phenyl ring.

The term “pharmaceutically acceptable salts” refers to the relativelynon-toxic, inorganic and organic acid addition salts and base additionsalts of compounds of the present invention. These salts can be preparedin situ during final isolation and purification of the compounds. Inparticular, acid addition salts can be prepared by separately reactingthe purified compound in its refined form with an organic or inorganicacid and isolating the resultant salt. Examples of acid addition saltsinclude hydrobromide, hydrochloride, sulfate, bisulfate, phosphate,nitrate, acetate, oxalate, valerate, oleate, palmitate, stearate,laurate, borate, benzoate, lactate, phosphate, tosylate, citrate,maleate, fumarate, succinate, tartrate, naphthylate, mesylate,glucoheptanate, lacto-bionate, sulfamates, malonates, salicylates,propionates, methylenebis-beta-hydroxynaphthoates, gentisic acid,isethionates, di-p-toluoyltartrates, methanesulfonates,ethanesulfonates, benzenesulfonates, p-toluenesulfonates, cyclohexylsulfamates and quinateslaurylsulfonate salts, and the like. (Forexample, see S. M. Berge et al. Pharmaceutical Salts, J. Pharm. Sci, 66:p. 1-19 (1977), which is included herein by reference.) Acid additionsalts can also be prepared by separately reacting the purified compoundin its acid form with an organic or inorganic base and isolating theresultant salt. Acid addition salts include amine and metal salts.Suitable metal salts include sodium, potassium, calcium, barium, zinc,magnesium and aluminium salts. Sodium and potassium salts are preferred.Suitable inorganic addition base salts are prepared from metal baseswhich include sodium hydride, sodium hydroxide, potassium hydroxide,calcium hydroxide, aluminium hydroxide, lithium hydroxide, magnesiumhydroxide, zinc hydroxide. Suitable base amine addition salts areprepared from amines which are sufficiently alkaline to form a stablesalt, and preferably include amines which are often used in medicinalchemistry because of their low toxicity and suitability for medical use:ammonia, ethylenediamine, N-methyl-glucamine, lysine, arginine,ornithine, choline, N,N′-dibenzylethylenediamine, chloroprocaine,diethanolamine, procaine, N-benzyl-phenethylamine, diethylamine,piperazine, tris(hydroxymethyl)-aminomethane, tetramethylammoniumhydroxide, triethylamine, dibenzylamine, ephenamine,dehydroabiethylamine, N-ethylpiperidine, benzylamine,tetramethylammonium, tetraethylammonium, methylamine, dimethylamine,trimethylamine, ethylamine, basic amine acids, for example lysine andarginine, and dicyclohexylamine and the like.

The invention also relates to pharmaceutically suitable stereoisomers ormixtures thereof, tautomeric forms, hydrates, solvates, salts and estersof compounds of formula (I).

Compounds of the invention of formula (I), as defined hereinbefore,having a sufficiently acidic group or a sufficiently basic group, orboth, can include the corresponding pharmaceutically acceptable organicor inorganic acid, or organic or inorganic base salts.

According to a further subject, the present invention also relates tothe process for preparing compounds of formula (I).

In the following embodiments and examples, group R6 represents group Y.

According to a first aspect, the compounds of formula (I) are preparedby coupling compounds of formulae (II) and (II′):

followed by hydrolysis, and optionally followed by derivatisation orderivatisations of the product of formula (I) obtained in order toacquire the desired product of formula (I).

This reaction is generally carried out using dimethyl-malonate, in thepresence of acetic anhydride. This process is illustrated by diagram 1.

The hydrolysis reaction is carried out generally using an acid, such as,for example, hydrochloric acid, or any other suitable acid.

According to a second aspect, the compounds of formula (I) are preparedby coupling compounds of formulae (III) and (III′):

optionally followed by derivatisation or derivatisations of the productof formula (I) obtained in order to acquire the desired product offormula (I).

Generally, this reaction is carried out using a base such as lithiumdiisopropylamine (LDA), followed by the addition of a compound offormula Hal-Z′-Hal, in which Z′ is selected so as to obtain thecorresponding group Z in general formula (I).

This process is illustrated in diagram 2.

Preferably, when K=2, it is preferable to start with (III) and (III′),by means of a base such as lithium diisopropylamine (LDA), followed bythe addition of CuCl₂ and treatment with EDTA. This process isillustrated in diagram 5.

According to a third aspect, the compounds of formula (I) are preparedby coupling compounds of formulae (IV) and (IV′):

in which Hal and Hal′ represent halogen atoms in the presence of a groupof formula HZH, optionally followed by derivatisation or derivatisationsof the product of formula (I) obtained in order to acquire the desiredproduct of formula (I).

Generally, this reaction is carried out in the presence of a catalystsuch as tris(dibenzylideneacetone)dipalladium(0) andrac-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl.

This process is illustrated in diagram 6.

According to a fourth aspect, the compounds of formula (I) are preparedby coupling compounds of formulae (V) and (V′):

in the presence of a group of formula Hal-Z-Hal, in which Hal representshalogen atoms, optionally followed by derivatisation or derivatisationsof the product of formula (I) obtained in order to acquire the desiredproduct of formula (I).

Generally, this reaction is carried out using a base such as lithiumdiisopropylamine (LDA), followed by the addition of a compound offormula Hal-Z-Hal, in which Z is selected so as to obtain thecorresponding group Z in general formula (I).

This process is illustrated in diagram 7.

According to a fifth aspect, the compounds of formula (I) are preparedby coupling compounds of formulae (VI) and (VI′):

in which Hal is a halogen atom in the presence of CuCl₂ and a base suchas Cs₂CO₃, optionally followed by derivatisation or derivatisations ofthe product of formula (I) obtained in order to acquire the desiredproduct of formula (I).

This process is illustrated in diagram 8.

According to a sixth aspect, the compounds of formula (I) are preparedby coupling compounds of formulae (VII) and (VII′):

optionally followed by derivatisation or derivatisations of the productof formula (I) obtained in order to acquire the desired product offormula (I).

Generally, this reaction is carried out in the presence of carboxylicacid energisers such as(benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphatecombined with hydroxybenzotriazole in the presence of a base such astriethylamine.

This process is illustrated in diagram 11.

According to a seventh aspect, the compounds of formula (I) are preparedby coupling compounds of formulae (VIII) and (VIII′):

optionally followed by derivatisation or derivatisations of the productof formula (I) obtained in order to acquire the desired product offormula (I).

Generally, this reaction is carried out in the presence of an iminereducing agent such as NaBHR₃.

This process is illustrated in diagram 12.

According to an eighth aspect, the compounds of formula (I) are preparedby coupling compounds of formulae (VIIII) and (VIIII′):

in the presence of a group of formula R″NH₂ optionally followed byderivatisation or derivatisations of the product of formula (I) obtainedin order to acquire the desired product of formula (I).

Generally, this reaction is carried out in the presence of an iminereducing agent such as NaBHR₃.

This process is illustrated in diagram 13.

According to a ninth aspect, the compounds of formula (I) are preparedby coupling the compound of formula (VV) and two compounds of formula(VV′):

in the presence of NH₃ optionally followed by derivatisation orderivatisations of the product of formula (I) obtained in order toacquire the desired product of formula (I).

Generally, this reaction is carried out in by means of an imine reducingagent such as NaBHR₃.

This process is illustrated in diagram 14.

According to a tenth aspect, the compounds of formula (I) are preparedby coupling compounds of formulae (VVI) and (VVI′):

optionally followed by derivatisation or derivatisations of the productof formula (I) obtained in order to acquire the desired product offormula (I).

Generally, this reaction is carried out in the presence of an iminereducing agent such as NaBHR₃.

This process is illustrated in diagram 15.

According to an eleventh aspect, the compounds of formula (I) areprepared by coupling compounds of formulae (VVII) and (VVII′):

in which Hal and Hal′ are halogen atoms in the presence of a group offormula RNH₂, optionally followed by derivatisation or derivatisationsof the product of formula (I) obtained in order to acquire the desiredproduct of formula (I).

Generally, this reaction is carried out by reacting (VVII) with RNH₂then coupling it with (VVII′) in the presence of a catalyst such astris(dibenzylideneacetone)dipalladium(0) andrac-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl.

This process is illustrated in diagram 16.

According to a twelfth aspect, the compounds of formula (I) are preparedby coupling compounds of formulae (VVIII) and (VVIII′):

optionally followed by derivatisation or derivatisations of the productof formula (I) obtained in order to acquire the desired product offormula (I).

Generally, this reaction is carried out in the presence of carboxylicacid energisers such as(benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphatecombined with hydroxybenzotriazole in the presence of a base such astriethylamine.

This process is illustrated in diagram 17.

The term “derivatisation” denotes any reaction which makes it possibleto modify or introduce groups on the starting molecules. This mayinvolve halogenation, alkylation, alkoxylation, addition, substitution,protection, deprotection, reduction, etc. These reactions are generallyknown per se. In the process according to the invention, these reactionscan be carried out by applying or adapting these methods.

Representative examples of these derivatisation reactions areillustrated in diagrams 1, 3, 4, 9, 10, 13, 14, 15 and 16.

Thus, the compounds of general formula (I) can be prepared by applyingor adapting any method known per se by and/or in the scope of a personskilled in the art, particularly those described by Larock inComprehensive Organic Transformations, VCH Pub., 1989, or by applying oradapting the processes described in the following examples.

Reaction intermediates are commercially available or can be prepared bya person skilled in the art by applying or adapting methods known perse.

The process according to the invention can also include the subsequentstage of isolation of the products of formula (I) obtained.

In the reactions described herein, it may be necessary to protect thereactive functional groups, for example the hydroxy, amino, imino, thioand carboxy groups if they are desired in the final product, so as toavoid undesirable participation thereof in the reactions. Traditionalprotecting groups can be used in accordance with the standard practice.For examples, see T. W. Greene and P. G. M. Wuts in Protective Groups inOrganic Chemistry, John Wiley and Sons, 1991; J. F. W. McOmie inProtective Groups in Organic Chemistry, Plenum Press, 1973.

The compound thus prepared can be recovered from the reaction mixture bytraditional means. For example, compounds can be recovered by distillingthe solvent from the reaction mixture or, if necessary, after distillingthe solvent from the solution, by pouring the remainder into water, thenextracting with a water-immiscible organic solvent, and distilling thesolvent from the extract. Furthermore, the product may, if so desired,still be purified using various techniques, such as recrystallisation,reprecipitation or the various chromatography techniques, in particularcolumn chromatography or preparative thin-layer chromatography.

It will be appreciated that the compounds which are useful according tothe present invention may have asymmetric centres. These asymmetriccentres can be independently in an R or S configuration. It will appearto a person skilled in the art that some compounds which are usefulaccording to the present invention may also have a geometric isomerism.It must be understood that the present invention includes individualgeometric isomers and stereoisomers and mixtures of thereof, includingracemic mixtures, of compounds from the aforementioned formula (I).Isomers of this type may be separated from their mixtures by applying oradapting known processes, for example chromatography techniques orrecrystallisation techniques, or they are prepared separately fromsuitable isomers of the intermediates thereof.

For the purposes of this text, it is understood that tautomeric formsare included in the citation of a given group, for example thio/mercaptoor oxo/hydroxy.

The acid addition salts are formed with the compounds that are usefulaccording to the invention in which a basic group, such as an amino,alkylamino or dialkylamino group, or even pyridine or phenol, ispresent. The pharmaceutically acceptable, i.e. non-toxic, acid additionsalts are preferred. The selected salts are optimally chosen so as to becompatible with the usual pharmaceutical vehicles and suitable for oralor parenteral administration. The acid addition salts of the compoundsthat are useful according to the present invention can be prepared byreacting the free base with the appropriate acid, by applying oradapting known processes. For example, the acid addition salts of thecompounds that are useful according to the present invention can beprepared either by dissolving the free base in water or in analcoholised aqueous solution or suitable solvents containing theappropriate acid, and isolating the salt by evaporating the solution, orby reacting the free base and the acid in an organic solvent, in whichcase the salt separates out directly or can be obtained by concentratingthe solution. Suitable acids for use in the preparation of these saltsinclude hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuricacid, various organic carboxylic and sulfonic acids, such as aceticacid, citric acid, propanoic acid, succinic acid, benzoic acid, tartaricacid, fumaric acid, mandelic acid, ascorbic acid, malic acid,methanesulfonic acid, toluenesulfonic acid, fatty acids, adipate,alginate, ascorbate, aspartate, benzenesulfonate, benzoate,cyclopentanepropionate, digluconate, dodecyl sulfate, bisulfate,butyrate, lactate, laurate, lauryl sulfate, malate, hydriodide,2-hydroxyethanesulfonate, glycerophosphate, picrate, pivalate, pamoate,pectinate, persulfate, 3-phenylpropionate, thiocyanate,2-naphthalenesulfonate, undecanoate, nicotinate, hemisulfate,heptonoate, hexanoate, camphorate, camphorsulfonate and the like.

The acid addition salts of the compounds that are useful according tothe present invention can be regenerated from the salts by applying oradapting known processes. For example, the parent compounds that areuseful according to the invention can be regenerated from their acidaddition salts by treatment with an alkali, for example aqueous sodiumbicarbonate solution or aqueous ammonia solution.

The compounds that are useful according to the present invention can beregenerated from the base addition salts thereof by applying or adaptingknown processes. For example, the parent compounds which are usefulaccording to the invention can be regenerated from their base additionsalts by treatment with an acid, for example a hydrochloric acid.

The base addition salts can be formed if the compound that is usefulaccording to the invention contains a carboxyl group, or else pyridineor phenol, or a sufficiently acidic bioisostere. The bases which can beused to prepare the base addition salts preferably include those thatproduce, if they are combined with a free acid, pharmaceuticallyacceptable salts, i.e. salts, the cations of which are not toxic to thepatient in the pharmaceutical doses of the salts, in such a way that thebeneficial inhibitory effects intrinsic in the free base are not negatedby the side effects attributable to the cations. The pharmaceuticallyacceptable salts, including those derived from alkaline-earth metalsalts, within the scope of the present invention, include those derivedfrom the following bases: sodium hydride, sodium hydroxide, potassiumhydroxide, calcium hydroxide, aluminium hydroxide, lithium hydroxide,magnesium hydroxide, zinc hydroxide, ammonia, ethylenediamine,N-methylglucamine, lysine, arginine, ornithine, choline,N,N′-dibenzylethylenediamine, chloroprocaine, diethanolamine, procaine,N-benzylphenethylamine, diethylamine, piperazine,tris(hydroxymethyl)aminomethane, tetramethylammonium hydroxide and thelike.

Compounds which are useful according to the present invention can beeasily prepared, or formed during the process of the invention, in theform of solvates (for example hydrates). Hydrates of the compounds thatare useful according to the present invention can be easily prepared byrecrystallisation of an aqueous/organic solvent mixture, using organicsolvents such as dioxane, tetrahydrofuran or methanol.

The basic products or the reagents used are commercially availableand/or can be prepared by applying or adapting known processes, forexample processes as described in the Reference Examples or obviouschemical equivalents thereof.

According to the present invention, compounds of formula (I) havebiological activity in metal chelation and/or amyloid aggregatedissolution.

The present invention also relates to pharmaceutical compositionscomprising a compound according to the invention having apharmaceutically acceptable vehicle or excipient.

Preferably, said composition contains an effective amount of thecompound according to the invention.

According to another subject, the present invention also relates to theuse of compounds of formula (I) for preparing pharmaceuticalcompositions intended to chelate metal ions, more preferably those ofzinc, copper, iron, aluminium or manganese, more preferably zinc ions atoxidation stage II, copper ions at oxidation stage I, II, and iron ionsat oxidation stage II, III, IV or V.

The invention also relates to the use of compounds of general formula(I) for the preparation of pharmaceutical compositions intended todissolve amyloid aggregates.

According to another subject, the invention also relates to the use ofcompounds of general formula (I) for the preparation of pharmaceuticalcompositions intended to prevent and/or treat neurodegenerativediseases. More particularly, the neurodegenerative diseases are selectedfrom Alzheimer's disease, Parkinson's disease, Huntington's disease,amyotrophic lateral sclerosis or Down syndrome, and spongiformencephalopathies, such as Creutzfeldt-Jakob's disease.

According to another subject, the present invention also relates tomethods for the aforementioned therapeutic treatment comprising theadministration of a compound according to the invention to a patient whorequires it.

Preferably, said composition is administered to a patient who requiresit.

Pharmaceutical compositions according to the invention may be presentedin forms intended for parenteral, oral, rectal, intravenous, permucosalor percutaneous administration.

Therefore, they will be presented in the form of solutes or injectablesuspensions or multi-dose vials, in the form of plain or coated tablets,dragees, capsules, gel capsules, pills, wafer capsules, powders,suppositories or rectal capsules, solutions or suspensions, forpercutaneous use in a polar solvent or for permucosal use.

The excipients suitable for such administrations are cellulose ormicrocrystalline cellulose derivatives, alkaline-earth metal carbonates,magnesium phosphate, starches, modified starches and lactose for solidforms.

For rectal use, cocoa butter or polyethylene glycol stearates are thepreferred excipients.

For parenteral use, water, aqueous solutes, physiological serum andisotonic solutes are the vehicles most appropriately used.

The dosage can vary within wide ranges (0.5 mg to 1000 mg) as a functionof the therapeutic indication and the method of administration, and alsoof the age and weight of the patient.

LEGENDS OF THE FIGURES

FIG. 1: Quinoline derivatives tested on A13.

FIG. 2: cis and trans configurations for complexing metal ions using8-hydroxyquinoline derivatives.

FIG. 3: Crystalline structure of[2,2′-(2,2-propanediyl)-bis[8-quinolinolato]nickel(II); the hydrogenatoms have been omitted. Note that the complex has a cis configuration(FIG. 2) and that the two quinoline entities of the ligand chelate thesame metal atom.

FIG. 4: Crystalline structure ofbis{7-(methyloxy)8-[phenylmethyl)oxy]-2-quinolinyl}propanedioate, thehydrogen atoms having been omitted.

FIG. 5: Crystalline structure of 2-chloro-8-nitroquinoline.

FIG. 6: UV-visible spectra obtained during the Cu(II) titration by theligand 3. Titration spectra are obtained with 15 μM of ligand (L) in the20 mM Tris-HCl buffer mixture containing 150 mM NaCl (pH=7.4)/CH₃OH(1/1, v/v) and different CuCl₂ ratios. The direction of the arrowsindicates variations observed on the spectra when the Cu(II)/L ratioincreases.

FIG. 7: UV-visible spectra of 3; Cu(II)-3; EDTA and (EDTA)Cu(II) in the20 mM Tris-HCl buffer mixture containing 150 mM NaCl (pH=7.4)/CH₃OH(1/1, v/v). The concentration of the ligands and metal complexes is 15μM. Note that an absorbency at λ=379 nm is only observed for theCu(II)-3 complex.

FIG. 8: Competition reaction for complexing CuCl₂ by the ligand 3(L_(s))and EDTA (L_(c)).

The spectra are obtained having 15 μM of 3 and CuCl₂ and different EDTAratios in the 20 mM Tris-HCl buffer mixture containing 150 mM NaCl(pH=7.4)/CH₃OH (1/1, v/v). The direction of the arrows indicatesabsorbency variations observed when the L_(c)/L_(s) ratio increases.

FIG. 9: Variation of the percentage of soluble Aβ₁₋₄₂ peptide as afunction of the Al/Cu(II) stoichiometry. The Aβ₁₋₄₂ (5 μM) peptide isincubated for two hours at 37° C. in a 20 mM Tris-HCl (pH=7.4) buffermixture containing 150 mM NaCl in the presence of different Cu(II)stoichiometries, then the reaction mixture is centrifuged. Thepercentage of peptide in the (soluble Aβ₁₋₄₂) supernatant and in the(aggregated Aβ₁₋₄₂) precipitate are thus quantified by means of a MicroBCA Protein Assays kit. Value 1 and Value 2 are from two independentexperiments, when the number of measures is ≧3, the mean and standarddeviation values obtained are presented.

FIG. 10: Percentage variation of soluble Aβ₁₋₄₂ peptide in the presenceof various CuCl₂ and ligand stoichiometries. Aβ₁₋₄₂ (5 μM) peptide isincubated for one hour at 37° C. in a 20 mM Tris-HCl (pH=7.4) buffermixture containing 150 mM NaCl in the presence of 12.5 or 20 μM CuCl₂,then the [12.5 μM (except for the quinoline monomers such as8-hydroxyquinoline, Clioquinol, 8-hydroxyquinaldine and 8-aminoquinolinewhere this value is 25 μM) or 200 μM] ligand is added. After a furtherhour of incubation, the reaction mixture is centrifuged. The percentageof peptide in the (soluble Aβ₁₋₄₂ supernatant and in the (aggregatedAβ₁₋₄₂ precipitate are thus quantified by means of a Micro BCA ProteinAssays kit. For each compound, the values on the left (in dark grey) andthe values on the right (in light grey) represent the results obtainedfor the 200 μM ligand/20 μM CuCl₂ and 12.5 μM (in the case of quinolinedimers or 25 μM in the case of monomers) ligand/12.5 μM CuCl₂ ratiosrespectively. Percentages of soluble Aβ₁₋₄₂ peptide in the presence ofdifferent concentrations of CuCl₂ in the absence of a ligand are alsoindicated..

FIG. 11: Variation in H₂O₂ production by copper complexes of Aβ₁₋₄₂peptide as a function of the Cu(II)/Aβ stoichiometry. Experiments arecarried out for 5 minutes in a sodium phosphate buffer (pH=7.4) in thepresence 0.4 μM CuCl₂, 10 μM ascorbate and air with or without 0.4 μM of3 or 7. The H₂O₂ released is quantified by means of an Amplex-RedH₂O₂/HRP Assay kit.

The following examples illustrate the invention, without limiting it.The initial products used are products known or prepared according toknown procedures.

The following abbreviations have been used hereinbefore or hereinafter:

Aβ: β-amyloid peptide; BSA: Bovine Serum Albumin; biPy: 2,2′-bipyridine;BnCl: benzyl chloride; BOP:(benzotriazole-1-yloxy)tris(dimethylamino)phosphoniumhexafluorophosphate; CTDA:trans-1,2-diaminocyclohexane-N,N,N′,N′-tetraacetic acid; d: doublet; rd:resolved doublet; CID: chemical ionisation detection; Dien:diethylenetriamine; DMF : dimethylformamide; DMSO: dimethylsulfoxide;DTPA: diethylene-triaminepentaacetic acid; EDA: ethylenediamine; EDDA:ethylenediamine-N,N′-diacetic acid; EDTA: ethylenediaminetetraaceticacid; EGTA: ethylenebis(oxyethylenenitrilo)-tetraacetic acid; eq:equivalent; Eq.: equation; HOBT: 1-hydroxybenzotriazole monohydrate;HRP: Horse Radish Peroxidase; HIDA: N-(2-hydroethyl)iminodiacetic acid;LDA: lithium diisopropylamine; m: mass; mCPBA: m-chloroperbenzoic acid;NBS: N-bromosuccinimide; NTA: nitrilotriacetic acid; Pd₂(dba)₂:tris(dibenzylidene-acetone)-dipalladium(0); MW: molecular weightrac-BINAP: rac-2,2′-bis(diphenylphosphino)-1,1′,binaphthyl; s: singletMS: mass spectrometry; t: triplet; Tetren: tetraethylenepentamine; THF:tetrahydrofuran; Trien: triethylenetetramine; rpm: revolutions perminute.

EXAMPLES Description of the Examples Synthesis: General RemarksConcerning Organic Synthesis:

8-methyloxyquinaldine was synthesised by a method described in theliterature. (C. Kitamura et al., J. Chem. Soc., Perkin Trans. 1 2000,781-785). N-butyl-2,2′-imino-bis(8-nitroquinoline) was synthesisedaccording to the references: H. Jiang et al. Tetrahedron 2003, 59,8365-8374; G. Xue et al., Tetrahedron 2001, 57, 7623-7628 and P. Belseret al. Tetrahedron 1996, 52, 2937-2944. 7-bromo-8-hydroxyquinoline(prepared according to the method of Pearson: D. E. Pearson et al. J.Org. Chem. 1967, 32, 2358-2360; G. E. Collis et al. Acta Cryst. 2003,C59, o443-o444). 1,1-dimethyl(2-formyl-8-quinolinyl)carbamate wassynthesised according to G. Xue et al., Tetrahedron 2001, 57, 7623-7628.2-Chloro-8-nitroquinoline was synthesised according to M. C. Kimber etal., Aust. J. Chem. 2003, 56, 39-44.

Acetonitrile was dried over a 4 Å molecular sieve. Tetrahydrofuran (THF)was distilled over benzophenone in the presence of sodium. Dry CuCl₂ wasobtained by heating under a vacuum at 50° C. Dichloromethane was driedover basic alumina. Other reagents and solvents used were provided bystandard suppliers of chemical products and were used without subsequentpurification.

NMR spectra were recorded on Bruker machines (200, 250 or 500 MHz). Theelectrospray ionisation mass spectrometer (ESI-MS/MS) was a Perkin-ElmerSCIEX API 365, the samples being fed into the electrospray source usinga Harvard Apparatus syringe pump. UV-visible spectra were recorded on aHewlett Packard 8452A diode spectrophotometer or a Perkin-Elmer Lamda 35spectrophotometer.

Thin-layer chromatography is carried out on silica plates.

Dimethyl-bis[8-(acetyloxy)-2-quinolinyl]propanedioate (Compound 1″)

The protocol was optimised using works by: Y. Yamamoto et al., Bull.Chem. Soc. Jpn. 1978, 51, 3489-3495. A suspension of8-hydroxyquinoline-N-oxide (4.47) g; 27.7 mmol) and dimethylmalonate3.35 ml; 29.1 mmol) in acetic anhydride (11.2 ml) is stirred for 27 daysat ambient temperature with protection from moisture (by means of a tubeof CaCl₂) and light. The orange suspension obtained is cooled at 0° C.and methanol (6.7 ml) is added. After 2 hours of stirring at ambienttemperature, water (30 ml) is added in two phases and the mixture isstirred for a further 2 hours. A precipitate is then collected andwashed with an acetic acid/water mixture (1/1, v/v, 30 ml) then water,before it is dried for 15 hours at 110° C. It is then dissolved hot inchloroform (15 ml) and precipitated by adding methanol (45 ml) to yielddimethyl-bis[8-(acetyloxy)-2-quinolinyl]propanedioate in the form of awhite powder (4.58 g; 9.12 mmol, yield=66%). NMR-¹H (250 MHz, CDCl₃) δ,ppm: 8.06 (d, ³J (H, H)=9.0 Hz, 2H); 7.87 (d, ³J (H, H)=9.0 Hz, 2H);7.64 (dd, ³J (H, H)=8.0 Hz, ⁴J (H, H)=1.5 Hz, 2H); 7.49 (m, 2H); 7.41(dd, ³J (H, H)=7.5 Hz, ⁴J (H, H)=1.5 Hz, 2H); 3.94 (s, 6H); 2.53 (s,6H). MS (CID, NH₃) m/z=503 (MH⁺). Analysis (%) for C₂₇H₂₂N₂O₈.0.5H₂O:calculated C 63.40; H 4.53; N 5.48; found C 63.46; H 4.10; N 5.56.

2,2′-methanediyl-bis(8-hydroxy-2-quinolinium)dichloride dihydrate(Compound 1′)

The protocol was optimised using works by: Y. Yamamoto et al., Bull.Chem. Soc.

Jpn. 1978, 51, 3489-3495. A suspension ofdimethyl-bis[8-(acetyloxy)-2-quinolinyl]propanedioate (4.00 g; 7.97mmol) in aqueous HCl at 20% (295 ml) is heated with reflux for 5 hours30 min then stirred for 4 hours at ambient temperature to yield a yellowprecipitate which is recovered and dried under vacuum. The product isthen dissolved hot in methanol (6.1 ml) which contains concentratedhydrochloric acid (610 μl) then crystallised by adding concentratedhydrochloric acid (6.1 ml) to yield2,2′-methanediyl-bis(8-hydroxy-2-quinolinium) dichloride dihydrate inthe form of yellow crystals (3.27 g; 7.96 mmol, quantitative yield).NMR-¹H (250 MHz, DMSO-d₆) δ, ppm: 8.72 (d, ³J (H, H)=9.0 Hz, 2H); 7.89(d, ³J (H, H)=9.0 Hz, 2H); 7.58 (m, 4H); 7.39 (dd, ³J (H, H)=7.5 Hz, ⁴J(H, H)=2.0 Hz, 2H); 5.14 (s, 2H). NMR-¹³C (100 MHz, DMSO-d₆) δ, ppm:156.5 (Cq); 151.3 (Cq); 142.7 (CH); 134.0 (Cq); 129.7(CH); 129.0 (Cq);124.3 (CH); 118.9 (CH); 115.1 (CH); 42.2 (CH₂). MS (CID, NH₃) m/z: 302(MH⁺). Analysis (%) for C₁₉H₁₂N₂O₂.2HCl.2H₂O: calculated C 55.49; H4.90; N 6.81; found C 55.95; H 4.79; N 6.66.

2,2′-methanediyl-bis(8-hydroxyquinoline) (Compound 1)

2,2′-methanediyl-bis(8-hydroxy-2-quinolinium) dichloride dihydrate (150mg; 0.36 mmol), suspended in 20 ml of CH₂Cl₂, is washed three times witha sodium acetate buffer (0.1 M; pH=7.0) then water. The solvent from theorganic phase is evaporated to yield, after drying under vacuum, 1 inthe form of an orange solid (110 mg, 0.36 mmol, quantitative yield).NMR-¹H (250 MHz, CDCl₃) δ, ppm: 8.20 (s large, 2H); 8.08 (d, ³J (H,H)=8.5 Hz, 2H); 7.43 (d, ³J (H, H)=8.5 Hz, 2H); 7.42 (m, 2H); 7.30 (dd,³J (H, H)=8.0 Hz, ⁴J (H, H)=1.0 Hz, 2H); 7.16 (dd, ³J (H, H)=7.5 Hz, ⁴J(H, H)=1.0 Hz, 2H); 4.69 (s, 2H). UV/vis [DMSO/20 mM Tris.HCl pH=7.4;150 mM NaCl (8/2, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=256 (50,800), 312 (8,700),454 (2,200), 480 (3,500), 512 (2,700).

2,2′-methanediyl-bis(5-chloro-8-hydroxyquinoline) (Compound 2)

The protocol was established using works by: H. Gershon, M. W. Mc Neil,J. Heterocycl. Chem. 1972, 9, 659-666. N-chlorosuccinimide (324 mg; 2.43mmol) is added batchwise to a suspension of2,2′-methanediyl-bis(8-hydroxy-2-quinolinium) dichloride dihydrate (500mg; 1.22 mmol) in H₂SO₄ at 97% (12 ml), cooled over an ice bath. Themixture is then stirred for 15 minutes at 0° C. then for 4 hours atambient temperature. It is subsequently poured over ice to yield a pinksuspension which is neutralised with an aqueous sodium hydroxidesolution. The mixture is then centrifuged. After removing thesupernatant, the precipitate is suspended in water and extracted withdichloromethane. The organic phase is washed in water and the solventsubsequently evaporated under vacuum to yield, after drying undervacuum, 2 in the form of a pale orange powder (440 mg; 1.19 mmol;yield=98%). NMR-¹H (250 MHz, CDCl₃) δ, ppm: 8.45 (d, ³J (H, H)=8.5 Hz,2H); 8.12 (s large, 2H); 7.56 (d, ³J (H, H)=8.5 Hz, 2H); 7.48 (d, ³J (H,H)=8.0 Hz, 2H); 7.10 (d, ³J (H, H)=8.0 Hz, 2H); 4.74 (s, 2H). NMR-¹³C(63 MHz, CDCl₃) δ, ppm: 157.4 (Cq); 151.0 (Cq); 138.1 (Cq); 134.2 (CH);127.2 (CH); 125.0 (Cq); 123.3 (CH); 120.4 (Cq); 110.3 (CH); 47.5 (CH₂).MS (CID, NH₃) m/z: 371 (MH⁺). Analysis (%) for C₁₉H₁₂Cl₂N₂O₂.0,1Na₂SO₄:calculated C 59.21; H 3.14; N 7.27; found C 59,27; H 2,58; N 7.05.UV/vis [dioxane/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1,v/v)]: λ nm (ε M⁻¹ cm⁻¹)=258 (59,900), 320 (7,000), 460 (2,000), 489(2,900), 518 (2,100).

[2,2′-(2,2-propanediyl)-bis[8-quinolinolato]nickel(II)

The synthesis was carried out according to the reference protocol: Y.Yamamoto et al., Bull. Chem. Soc. Jpn. 1978, 51, 3489-3495. NMR datawhich are more specific than those previously published are addedhereinafter. NMR-¹H (250 MHz, CDCl₃) δ, ppm: 8.15 (d, ³J (H, H)=9.0 Hz,2H); 7.45 (d large, ³J (H, H)=9.0 Hz, 2H); 7.33 (m, 2H); 6.91 (d large,³J (H, H)=7.5 Hz, 2H); 6.81 (d large ³J (H, H)=6.5 Hz, 2H); 1.93 (s,6H). NMR-¹³C (63 MHz, CDCl₃) δ, ppm: 166.4 (Cq); 159.1 (Cq); 144.3 (Cq);138.7 (CH); 130.7 (CH); 127.7 (Cq); 119.3 (CH); 113.6 (Cq); 110.4 (CH);50.7 (CH₃). MS(CID, NH₃): m/z=387 (MH⁺), 404 (MNH₄ ⁺). The moleculestructure was confirmed by X-ray diffraction analysis of monocrystalsobtained by crystallisation of the product in methanol. The structure ofthe complex is presented in FIG. 3. The parameters for crystal analysisare as follows: triclinic crystal system, P-1; a=12.456(4) Å,b=12.650(4) Å, c=13.983(5) Å, α=112.260(5)°, β=105.956(5)°,γ=90.115(6)°.

2,2′-(2,2-propanediyl)-bis(8-hydroxyquinoline) (Compound 3)

The protocol was optimised using works by: Y. Yamamoto et al., Bull.Chem. Soc. Jpn. 1978, 51, 3489-3495. Red crystals of[2,2′-(2,2-propanediyl)-bis[8-quinolinolato]nickel(II) (3.32 g; 8.60mmol) are suspended in 80 ml of ethanol then 16 ml of concentratedhydrochloric acid is added to yield a green solution to which 320 ml ofboiling water are added batchwise to form yellow crystals. Aftercooling, the crystals are collected and washed with a 1M aqueous HClsolution then dried in the air at ambient temperature for 15 hours priorto being dissolved hot again in 32 ml of ethanol. A boiling 18.4 mMaqueous solution of sodium acetate is then added batchwise. Aftercooling, a precipitate is recovered by centrifugation then washed inwater and extracted with dichloromethane to yield, after evaporation ofthe solvent and drying under vacuum, 3 in the form of a white solid(1.81 g). The precipitation supernatant from the previous stage, whichcontains a residual amount of the nickel complex, is neutralised with a6 M aqueous sodium hydroxide solution then 1 l of dichloromethane isadded; the product is stripped using an aqueous solution ofethylenediaminetetraacetic acid (2×10 g in 500 ml) and stirred for 1hour. The organic phase is recovered, washed in water, then concentratedunder vacuum. The mixture is then purified by chromatography over silicagel using a gradient of 0 to 1% of CH₃OH in CH₂Cl₂ (v/v) to yield afurther 0.83 g of 3 in the form of a white solid (total mass=2.64 g;8.00 mmol, yield=93%). NMR-¹H (250 MHz, CDCl₃) δ, ppm: 8.30 (s large,2H); 8.02 (d, ³J (H, H)=9.0 Hz, 2H); 7.45 (m, 2H); 7.30 (dd, ³J (H,H)=7.5 Hz, ⁴J (H, H)=1.0 Hz, 2H); 7.22 (d,³J (H, H)=9.0 Hz 2H); 7.21(dd,³J (H, H)=7.5 Hz, ⁴J (H, H)=1.0 Hz, 2H); 2.0 (s, 6H). NMR-¹³C (63MHz, CDCl₃) δ, ppm: 164.7 (Cq); 152.1 (Cq); 136.8 (Cq); 136.5 (CH);127.5 (CH); 126.8 (Cq); 121.2 (CH); 117.5 (Cq); 110.3 (CH); 49.3 (Cq);28.0 (CH₃). MS (CID, NH₃) m/z: 331 (MH⁺). Analysis (%) for C₂₁H₁₈N₂O₂:calculated C 76.34; H 5.49; N 8.48; found C 75.80; H 5.30; N 8.38.UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]:λ nm (ε M⁻¹ cm⁻¹)=203 (77,700), 251 (84,600), 308 (6,900).

2,2′-(2,2-Propanediyl)-bis(5-chloro-8-hydroxyquinoline) (Compound 4)

The protocol was established using works by: H. Gershon et al., J.Heterocycl. Chem. 1972, 9, 659-666. N-chlorosuccinimide (40 mg; 0.30mmol) is added batchwise to a solution of 3 (50 mg; 0.15 mmol) in H₂SO₄at 97% (1,5 ml) and cooled over an ice bath. The mixture is then stirredfor 15 minutes at 0° C. then for 3 hours at ambient temperature. It issubsequently poured over ice to yield a yellow suspension which isneutralised with a 3 M aqueous solution of sodium hydroxide. The mixtureis centrifuged, the supernatant is removed then the precipitate issuspended in water and extracted with dichloromethane. The organic phaseis washed in water and the solvent subsequently evaporated to yield 4 inthe form of a white powder (55 mg; 0.14 mmol; yield=93%). NMR-¹H (250MHz, CDCl₃) δ, ppm: 8.37 (d, ³J (H, H)=9.0 Hz, 2H); 8.19 (s large, 2H);7.50 (d, ³J (H, H)=8.0 Hz, 2H); 7.32 (d, ³J (H, H)=9.0 Hz,2H); 7.13 (d,³J (H, H)=8.2 Hz, 2H); 2.00 (s, 6H). NMR-¹³C (63 MHz, CDCl₃) δ, ppm:165.2 (Cq); 151.1 (Cq); 137.3 (Cq); 134.0 (CH); 127.2 (CH); 124.7 (Cq);121.9 (CH); 120.5 (Cq); 110.2 (CH); 49.4 (Cq); 27.9 (CH₃). MS (CID, NH₃)m/z: 399 (MH⁺). Analysis (%) for C₂₁H₁₆Cl₂N₂O₂: calculated C 63.17; H4.04; N 7.02; found C 63.02; H 3.76; N 6.87. UV/vis [dioxane/20 mMTris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹cm⁻¹)=258 (72,500), 315 (8,300).

2,2′-(Difluoromethanediyl)-bis(8-hydroxyquinoline) (Compound 5)

1-chloromethyl-4-fluoro-1,4-diazoniabicyclo(2,2,2)octanebis(tetrafluoroborate) (F-TEDA-BF₄, Selectfluor™, 258 mg; 0.73 mmol) isadded batchwise under nitrogen to an orange suspension of2,2′-methanediyl-bis(8-hydroxy-2-quinoline) (compound 1 110 mg; 0.36mmol) in 30 ml dry d′acetonitrile, which leads to solubilisation of theproducts in the form of a yellow solution. The mixture is stirred for 90minutes at ambient temperature. After evaporation of the solvent, theproduct is solubilised in dichloromethane and washed twice in water. Theorganic phase is concentrated and dried under vacuum to yield 5 in theform of a yellow powder (123 mg; 0.36 mmol, quantitative yield). NMR-¹H(250 MHz, CDCl₃) δ, ppm: 8.34 (d, ³J (H, H)=8.5 Hz, 2H); 8.00 (d, ³J (H,H)=8.5 Hz, 2H); 7.78 (s, 2H);=7.52 (m, 2H); 7.39 (dd, ³J (H, H)=8.0 Hz,⁴J (H, H)=1.0 Hz, 2H); 7.19 (dd, ³J (H, H)=7.5 Hz, ⁴J (H, H)=1.0 Hz,2H). NMR-¹³C (126 MHz, CDCl₃) δ, ppm: 152.3 (t, ²J (C, F)=30.0 Hz, Cq);152.3 (Cq); 137.6 (CH); 137.2 (Cq); 129.3 (CH); 128.5 (Cq); 118.7 (t,³J(C, F)=3.5 Hz, CH); 117.9 (CH); 117.0 (t, ¹J (C, F)=245.6 Hz, Cq);111.0 (CH). NMR-¹⁹F (188 MHz, CDCl₃, reference: CF₃CO₂H) δ, ppm: −22.2.MS (CID, NH₃) m/z: 339 (MH⁺, 356 (MNH₄ ⁺). Analysis (%) forC₁₉H₁₂F₂N₂O₂.0,3 H₂O: calculated C 66.39; N 3.69; N 8.15; found C 66.25;H 3.62; N 8.27. Uv/vis [CH₃OH/20 mM Tris-HCl pH=7.4 containing 150 mMNaCl (1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=241 (50,000), 251 (55,600), 314(4,700).

Bis(8-hydroxy-2-quinoline)methanone (Compound 6)

2,2′-methanediyl-bis(8-hydroxy-2-quinolinium) dichloride dehydrate (60mg; 0.16 mmol) is stirred into 8 ml of a THF/saturated aqueous solutionof NaHCO₃ (1/1, v/v) mixture for 48 hours. 10 ml of CH₂Cl₂ and 10 ml ofwater are then added and the reaction mixture is transferred to aseparating funnel. The organic phase is recovered and the aqueous phaseis subsequently extracted with CH₂Cl₂ (2×10 ml). The organic phases arecombined and washed in water (1×10 ml), then the solvent is evaporatedunder vacuum. The product is then purified by filtration over silica gelwith a CH₂Cl₂/CH₃OH) (97/3, v/v) mixture as solvent. Evaporation of thesolvent from the filtrate yields 6 in the form of a red powder (42 mg;0.13 mmol, yield=81%). NMR-¹H (250 MHz, CDCl₃) δ, ppm: 8.36 (d, ³J (H,H)=8.5 Hz, 2H); 8.19 (d, ³J (H, H)=8.5 Hz, 2H); 8.04 (s large, 2H); 7.59(m, 2H); 7.43 (dd, ³J (H, H)=8.5 Hz,⁴J (H, H)=1.0 Hz, 2H); 7.22 (dd, ³J(H, H)=7.5 Hz, ⁴ (H, H)=1.0 Hz, 2H). NMR-¹³C (126 MHz, CDCl₃) δ, ppm:192.2 (Cq); 153.1 (Cq); 151.4 (Cq); 137.1 (Cq); 137.0 (CH); 130.4 (CH);129.5 (Cq); 121.8 (CH); 117.9 (CH); 111.2 (CH). MS (CID, NH₃) m/z: 317(MH⁺). Analysis (%) for C₁₉H₁₂N₂O₃.0.5H₂O: calculated C 70.15; H 4.03; N8.61; found C 70.11; H 3.83; N 8.94. UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=254 (43,300), 273(26,100), 310 (9,600 shoulder), 375 (2,300).

2,2′-(1,2-Ethanediyl)-bis[8-(methyloxy)quinoline] (Compound 7′)

The product has already been described in: C. Kitamura et al., J. Chem.Soc., Perkin Trans. 1 2000, 781-785, but the protocol is different andwas established using the synthesis of another product by T. Garber etal., Inorg. Chem. 1990, 29, 2863-2868. A solution under argon of8-methoxyquinaldine (5.32 g; 30.75 mmol) in 47 ml of dry THF is cooledto −95° C. using a methanol/liquid nitrogen mixture. A 1.5 M solution oflithium diisopropylamine THF in cyclohexane (20.5 ml; 30.7 mmol) and dryTHF (63 ml) is added over 2 hours. The solution is stirred for a further2 hours at −95° C., then 1,2-dibromoethane (5.30 ml; 61.5 mmol) isadded. The mixture is brought to ambient temperature and stirred for 15hours. Water (32 ml) is then added, leading to the formation of a whiteprecipitate which is recovered by filtration. The filtrate isconcentrated under vacuum and subjected to silica gel columnchromatography eluted with a gradient of 0 to 90% of ethyl acetate inCHCl₃ (v/v). The product obtained by chromatography and the precipitateare combined and crystallised hot in methanol to yield2,2′-(1,2-ethanediyl)-bis[8-(methyloxy)quinoline] in the form of a whitesolid (2.04 g; 5.93 mmol, yield=38%). NMR-¹H (250 MHz, CDCl₃) δ, ppm:8.04 (d, ³J (H, H)=8.5 Hz, 2H); 7.40 (d, ³J (H, H)=8.5 Hz, 2H); 7.39 (m,2H); 7.35 (dd, ³J (H, H)=8.0 Hz, ⁴J (H, H)=1,5 Hz, 2H); 7.06 (dd, ³J (H,H)=7.5 Hz, ⁴J (H, H)=1.5 Hz, 2H); 4.10 (s, 6H); 3.61 (s, 4H). MS (CDI,NH₃): m/z (%)=345 (MH⁺).

2,2′-(1,4-Butanediyl)-bis[8-(methyloxy)quinoline] (Compound 10′)

It is obtained as the main by-product in the methanol supernatant fromcrystalllisation of 2,2′-(1,2-ethanediyl)-bis[8-(methyloxy)-quinoline].A second crystallisation in the methanol makes it possible to obtain apure methanol solution of the desired product. The solvent is thenevaporated to yield, after drying under vacuum,2,2′-(1,4-butanediyl)-bis[8-(methyloxy)-quinoline] in the form of awhite powder (0.68 g; 1.84 mmol, yield=6%). NMR-¹H (250 MHz, CDCl₃) δ,ppm: 8.01 (d, ³J (H, H)=8.5 Hz, 2H); 7.40 (d, ³J (H, H)=8.5 Hz, 2H);7.39 (m, 2H); 7.35 (dd, ³J (H, H)=8.0 Hz, ⁴J (H, H)=1.5 Hz, 2H); 7.06(dd, ³J (H, H)=7.5 Hz, ⁴J (H, H)=1.5 Hz, 2H); 4.01 (s, 6H); 3.10 (m,4H); 1.95 (m, 4H). MS (CDI, NH₃): m/z=373 (MH⁺).

2,2′-(1,2-Ethanediyl)-bis(8-hydroxyquinoline) (Compound 7)

The product has already been described in: C. Kitamura et al., J. Chem.Soc., Perkin Trans. 1 2000, 781-785, from which this stage of synthesiswas very slightly altered. It has also been described but obtained byanother method of synthesis in: M. Albrecht et al., Synthesis 1999, 10,1819-1829. A solution of2,2′-(41,2-ethanediyl)-bis[8-(methyloxy)quinoline] (2.83 g; 8.23 mmol)in 48% hydrobromic acid (150 ml) is heated under reflux for 24 hours.After cooling to ambient temperature, the mixture is neutralised with a3M aqueous solution of sodium hydroxide, leading to the formation of agreen precipitate. The product is extracted with dichloromethane thenwashed in water and brine. The organic phase is dried over Na₂SO₄ andthe solvent is evaporated under vacuum to yield 7 in the form of a palegreen powder (2.53 g; 8.00 mmol, yield=97%). NMR-¹H (250 MHz, CDCl₃) δ,ppm: 9.35 (s large, 2H); 8.20 (d, ³J (H, H)=8.5 Hz, 2H); 7,53 (d, ³J (H,H)=8.5 Hz, 2H); 7.37 (m, 2H); 7.32 (dd, ³J (H, H)=6.5 Hz, ⁴J (H, H)=2.0Hz, 2H); 7.05 (dd, ³J (H, H)=6.5 Hz, ⁴J (H, H)=2,0 Hz, 2H); 3.57 (s,4H). MS (CID, NH₃) m/z: 317 (MH⁺). Analysis (%) for C₂₀H₁₆N₂O₂.0.1NaBr:calculated C 73.53; H 4.93; N 8.58; found C 73.81; H 4.73; N 8.50.UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]:λ nm (ε M⁻¹ cm⁻¹)=204 (71,800), 248 (74,200), 305 (5,200).

2,2′-(1,4-Butanediyl)-bis(8-hydroxyquinoline) (Compound 10)

The protocol was established from the works of C. Kitamura et al., J.Chem. Soc., Perkin Trans 1 2000, 781-785 on the previous product.2,2′-(1,4-butanediyl)-bis[8-(methyloxy)quinoline] (50 mg, 0.13 mmol) isheated under reflux in hydrobromic acid at 48% (2.7 ml) for 24 hours.After cooling to 4° C. using an ice bath, the reaction mixture isbasified to pH=8 with a 3M aqueous solution of sodium hydroxide (5 ml,15 mmol) and a saturated aqueous solution of NaHCO₃ (2 ml). The volumeis made up to 15 ml with water and the aqueous phase is extracted withCH₂Cl₂ (3×10 ml). The organic phases are combined, washed in water (10ml), then the solvent is evaporated under vacuum. The product is thenpurified using silica gel flash chromatography eluted with aCH₂Cl₂/CH₃OH/CH₃COOH (96/3/1, v/v/v) mixture. The last fractions arecombined, the solvent is evaporated and the fractions are dissolvedagain in a mixture of 10 ml of CH₂Cl₂ and sodium acetate buffer (10 ml;0.1 M, pH=7.0). The organic phase is recovered and after evaporation ofthe solvent yields 10 in the form of a white powder (34 mg; 0.10 mmol;yield=77%). NMR-¹H (250 MHz, CDCl₃) δ, ppm: 8.04 (d, ³J (H, H)=8.5 Hz,2H); 7.38 (m, 2H); 7.31-7.25 (m, 4H); 7.15 (dd, ³J (H, H)=7.5 Hz, ⁴J (H,H)=1.0 Hz, 2H); 3.02 (m, 4H); 1.93 (m, 4H). MS (CID, NH₃) m/z: 345(MH⁺). Analysis (%) for C₂₂H₂₀N₂O₂.0.25H₂O: calculated C 75.73; H 5.92;N 8.35; found C 75.39; H 5.69; N 8.63. UV/vis [CH₃OH/20 mM Tris-HClpH=7.4 containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=202(81,300), 244 (90,800), 303 (6,300).

2,2′-(1.2-Ethanediyl)-bis(5-chloro-8-hydroxyquinoline 8) (Compound 8)

The protocol was established from the works of C. Kitamura et al., J.Heterocycl. Chem. 1972, 9, 659-666. N-chlorosuccinimide (253 mg; 1.90mmol) is added batchwise to a solution of 7 (300 mg; 0.95 mmol) in 97%H₂SO₄ (9.5 ml) and cooled over an ice bath. The mixture is stirred for15 minutes at 0° C. then for 3 hours at ambient temperature. It issubsequently poured over ice to yield a yellow suspension which isneutralised with a 3M aqueous solution of sodium hydroxide. A greenprecipitate is then filtered and dried under vacuum prior to beingdissolved in 200 ml of dimethylformamide and precipitated twice at 4° C.with 200 ml of water and filtered to yield after drying 8 in the form ofa pale green solid (258 mg; 0.67 mmol, yield=71%). NMR-¹H (250 MHz,DMSO-d₆) δ, ppm: 9.73 (s large, 2H); 8.37 (d, ³J (H, H)=8.5 Hz, 2H);7.70 (d, ³J (H, H)=8.5 Hz, 2H); 7.52 (d, ³J (H, H)=8.0 Hz, 2H); 7.06 (d,³J (H, H)=8.0 Hz, 2H); 3.64 (s, 4H). NMR-¹³C (100 MHz, DMSO-d₆) δ, ppm:161.5 (Cq); 153.0 (Cq); 139.2 (CH); 133.5 (Cq); 127.4(CH); 125.4 (Cq);124.4 (CH); 119.6 (CH); 112.1 (CH); 37.1 (CH₂). NMR observation of the¹H/¹³C correlation points between C5 and H4 made it possible to assignthe halogen position. MS (CID, NH₃) m/z: 385 (MH⁺). Analysis (%) forC₂₀H₁₄Cl₂N₂O₂.0.1Na₂SO₄: calculated C 60.14; H 3.53; N 7.01; found C59.92; H 2.58; N 6.65. UV/vis [dioxane/20 mM Tris-HCl pH=7.4 containing150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=254 (75,000), 313 (7,200).

2,2′-(1,2-Ethanediyl)-bis(5-chloro-7-iodo-8-hydroxyquinoline) (Compound9)

The protocol was established from works by: H. Gershon et al., J.Heterocycl. Chem. 1972, 9, 659-666. 250 μλ of 97%H₂SO₄ is added to asolution of 8 (300 mg; 0.78 mmol) in 12 ml of methanol, under N₂, toyield a yellow suspension which is cooled over an ice bath.N-iodosuccinimide (418 mg; 1.86 mmol) is then added slowly and themixture is stirred for 15 minutes at 0° C. then for 5 days at ambienttemperature. It is subsequently poured over ice and decoloured by addingNa₂S₂₅ (450 mg). The suspension is neutralised with ammonia andcentrifuged. The supernatant is removed, the precipitate is dissolved indichloromethane and washed with Tris-HCl (0.1 M=7.0) buffer. The solventfrom the organic phase is evaporated under vacuum to yield 9 in the formof a yellow powder (350 mg; 0.55 mmol, yield=70%). NMR-¹H (250 MHz,DMSO-d₆) δ, ppm: 8.36 (d, ³J (H, H)=8.5 Hz, 2H); 7.90 (s, 2H); 7.70 (d,³J (H, H)=8.7 Hz, 2 H); 3.68 (s, 4H). NMR-¹³C (63 MHz, DMSO-d₆) δ, ppm:162.1 (Cq); 153.1 (Cq); 137.3 (CH); 134.4 (Cq); 133.5(CH); 124.6 (Cq);124.5 (CH); 120.2 (CH); 78.4 (CH); 37.1 (CH₂). MS (CID, NH₃) m/z: 637(MH⁺). Analysis (%) for C₂₀H₁₄Cl₂I₂N₂O₂: calculated C 37.71; H 1.90; N4.40; found C 38.15; H 2.04; N 4.15. UV/vis [dioxane/20 mM Tris-HClpH=7.4 containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=262(69,500), 319 (7,900).

2,2′,2″-(1,2,3-Propanetriyl)-tris[8-(methyloxy)quinoline] (Compound 11′)

A 1.5 M solution of lithium diisopropylamine THF in cyclohexane (20 ml;30.52 mmol) is added to a solution of 8-methyloxyquinaldine (1.41 g;8.14 mmol) in dry THF (20 ml), under argon and cooled over an ice bath,for a period of 1 minute. The solution is stirred for 1 hour at 4° C.then dry CuCl₂ (1.32 g; 9.81 mmol) is added and the mixture is stirredfor 36 hours at ambient temperature under argon. Water (100 ml) is thenadded and the product is extracted with chloroform, washed with brineand the solvent is evaporated. The product is then subjected to silicagel column chromatography eluted with a gradient of 20 to 100% of ethylacetate in CHCl₃ (v/v). The resulting product is dissolved indichloromethane and washed with an EDTA aqueous solution to remove anytraces of copper ion, then subjected to chromatography again, accordingto the earlier conditions, to yield2,2′,2″-(1,2,3-propanetriyl)-tris[8-(methyloxy)quinoline] in the form ofa white powder (150 mg; 0.29 mmol, yield=11%). NMR-¹H (250 MHz, CDCl₃)δ, ppm: 7.81 (d, ³J (H, H)=8.5 Hz, 1H); 7.75 (d, ³J (H, H)=8.5 Hz, 2H);7.37-7.18 (m, 9H), 7.00 (dd, ³J (H, H)=7.5 Hz, ⁴J (H, H)=1.5 Hz, 1H);6.95 (dd, ³J (H, H)=7.5 Hz, ⁴J (H, H)=1.5 Hz, 1H); 4.49 (ABX system,³J_(AX) (H, H)=8.0 Hz, ³J_(BX) (H, H)=7.0 Hz, 1H); 4.05 (s, 3H); 4.01(s, 6H); 3.78 (ABX system, ²J_(AB) (H, H)=14.0 Hz, ³J_(AX)(H, H)=8.0 Hz,2H); 3.62 (ABX system, ²J_(AB) (H, H)=14.0 Hz, ³J_(BX) (H, H)=7.0 Hz,2H). MS (CDI, NH₃): m/z=516 (MH⁺).

2,2′,2″-(1,2,3-Propanetriyl)-tris(8-hydroxyquinoline) (Compound 11)

2,2′,2″-(1,2,3-propanetriyl)-tris[8-(methyloxy)quinoline] (30 mg; 0.058mmol) is heated under reflux in hydrobromic acid at 48% (1.2 ml) for 36hours. The acid is evaporated under vacuum and the residue is dissolvedin a mixture of 10 ml of CH₂Cl₂ and 10 ml of sodium acetate buffer (0.1M; pH=7.0). The organic phase is collected and the aqueous phase issubsequently extracted with CH₂Cl₂ (2×10 ml). The organic phases arecombined, washed in water (10 ml), and the solvent subsequentlyevaporated under vacuum to yield 11 in the form of an orange powder (20mg; 0.042 mmol; yield=73%). NMR-¹H (250 MHz, CDCl₃) δ, ppm: 7.94 (d, ³J(H, H)=8.0 Hz, 1H); 7.91 (d, ³J (H, H)=8.0 Hz, 2H); 7.42-7.10 (m, 12H);4.47 (ABX system, ³J_(AX)(H, H)=8.0 Hz, ³J_(BX)(H, H)=6.5 Hz, 1H); 3.71(ABX system, ²J_(AB)(H, H)=14.5 Hz, ³J_(AX)(H, H)=8.0 Hz, 2H); 3.57 (ABXsystem, ²J_(AB) (H, H)=14.5 Hz, ³J_(BX)(H, H)=6.5 Hz, 2H). MS (CDI,NH₃): m/z=474 (MH⁺). Analysis (%) for C₃₀H₂₃N₃O₃.0.5H₂O: calculated C74.67; H 5.01; N 8.71; found C 74.54; H 5.09; N 9.19. UV/vis [CH₃OH/20mM tris.HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹cm⁻¹)=204 (106,000), 248 (113,000), 302 (9,200).

Bis(8-quinoline)amine (Compound 12)

It was prepared according to J. C. Peters et al., Inorg. Chem. 2001, 40,5083-5091. In summary: a suspension under argon oftris(dibenzylidene-acetone)-dipalladium(0) (4.4 mg, 5 μmmol) andrac-2,2′-bis(diphenylphosphino)-1,1′, binaphthyl (6.0 mg, 10 μmmol) in750 μl of toluene is stirred for 5 minutes at ambient temperature then8-bromoquinoline (50 mg, 0.24 mmol), 8-aminoquinoline (35 mg, 0.24 mmol)and 1.75 ml of toluene are added to the suspension. By addingtertio-sodium butanolate (28 mg; 0.29 mmol), a red solution is formedand this is stirred for 3 days at 110° C. After cooling, the solution isfiltered over silica and extracted using dichloromethane. The organicphase is concentrated to yield a red solid, which is purified by silicagel chromatography eluted by means of a toluene/ethyl acetate (4/1, v/v)mixture to yield 12 in the form of an orange solid (44.0 mg, 0.16 mmol,yield=67%). NMR-¹H (250 MHz, CDCl₃) δ, ppm: 10.62 (s large, 1H); 8.96(dd, ³J (H, H)=4.0 Hz, ⁴J (H, H)=1.5 Hz, 2H); 8.16 (dd, ³J (H, H)=8.5Hz, ⁴J (H, H)=1.5 Hz, 2H); 7.90 (dd, ³J (H, H)=7.5 Hz, ⁴J (H, H)=1.0 Hz,2H); 7.53 (m, 2H); 7.46 (m, 2H); 7.34 (dd, ³J (H, H)=6.5 Hz, ⁴J (H,H)=1.0 Hz, 2H). MS (CDI, NH₃): m/z=272 (MH⁺). UV/vis [DMSO/20 mM Tris-HCpH=7.4 containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=268(43,700), 341 (5,100), 399 (16,900).

N,N′-di-8-quinolinyl-1,3-propanediamine (Compound 13)

A suspension under argon of tris(dibenzylideneacetone)dipalladium(0) (55mg, 0.06 mmol) and rac-2,2′-bis(diphenylphosphino)-1,1′, binaphthyl (75mg, 0.12 mmol) in 6 ml of toluene is stirred for 5 minutes at ambienttemperature then 8-bromoquinoline (500 mg, 314 l, 2.40 mmol),1,3-diaminopropane (89 mg, 100 μl, 1.20 mmol) and 6 ml of toluene areadded to the suspension. By adding tertio-sodium butanolate (323 mg;3.36 mmol), a red solution is formed and this is stirred for 3 days at100° C. After cooling, the solution is filtered over silica andextracted using dichloromethane. The organic phase is concentrated toyield a violet solid which is purified by silica gel chromatographyeluted with a gradient of 0 to 5% of CH₃OH in CH₂Cl₂ (v/v). After thesolvent has evaporated, the product is taken up in dichloromethane andprecipitated at 4° C. by adding 4 equivalents of HCl (in the form of a 1M solution in diethyl ether). The precipitate is recovered and dissolvedagain in water, the solution is alkalinised using ammonia until thepH=10, and the product is extracted with dichloromethane to yield, afterevaporation of the solvent and drying under vacuum, 13 in the form of abrown powder (355 mg, 1.08 mmol, yield=90%). NMR-¹H (250 MHz, CDCl₃) δ,ppm: 8.70 (dd, ³J (H, H)=4.0 Hz, ⁴J (H, H)=1.5 Hz, 2H); 8.06 (dd, ³J (H,H)=8.0 Hz, ⁴J (H, H)=1.5 Hz, 2H); 7.37 (m, 4H); 7.05 (dd, ³J (H, H)=8.0Hz, ⁴J (H, H)=0.5 Hz, 2H); 6.71 (dd, ³J (H, H)=8.0 Hz, ⁴J (H, H)=0.5 Hz,2H); 6.24 (t large, ³J (H, H)=5.0 Hz, 2H); 3.55 (m, 4H); 2.27(quintuplet, ³J (H, H)=7.0 Hz, 2H). NMR-¹³C (126 MHz, CDCl₃) δ, ppm:146.8 (CH); 144.8 (Cq); 138.3 (Cq); 136.0 (CH); 128.7 (Cq); 127.8 (CH);121.4 (CH); 113.8 (CH); 104.7 (CH); 41.3 (CH₂); 29.0 (CH₂). MS (CDI,NH₃): m/z=329 (MH⁺).

N,N′-bis(2-methyl-8-quinolinyl)-1,2-ethanediamine (Compound 14)

A solution under argon of 8-aminoquinaldine (0.50 g; 3.16 mmol) in 5 mlof dry THF is cooled to −90° C. by means of a methanol/liquid nitrogenmixture. A 1.5 M solution of lithium diisopropylamine THF in cyclohexane(4.2 ml; 6.33 mmol) in 7.5 ml of THF is added over 30 minutes. Thesolution is stirred for a further 90 minutes at −95° C., then1,2-dibromoethane (0.55 ml; 6.33 mmol) is added dropwise. The mixture isbrought to ambient temperature and stirred for 15 hours. Water (6 ml) isthen added and the mixture is stirred for 90 minutes at ambienttemperature. The THF is evaporated under reduced pressure and theaqueous phase is extracted with CH₂Cl₂ (2×75 ml). The organic phase iswashed with 75 ml of a saturated aqueous solution of NaHCO₃ then with 75ml of H₂O and the solvent is evaporated under reduced pressure. Thecrude product of the reaction is then subjected to silica gel columnchromatography, eluted with a gradient of 0 to 100% of ethyl acetate inCH₂Cl₂ (v/v). Fractions containing the product are combined and thesolvent is evaporated. The product is dissolved again in 1 ml of CH₂Cl₂and precipitated by adding 6 ml of hexane. It is subsequently filteredthen rinsed in hexane to yield, after drying under vacuum, 14 in theform of a white powder (34 mg; 0.10 mmol; yield=6%). NMR-¹H (250 MHz,CDCl₃) δ, ppm: 7.95 (d, ³J (H, H)=8.5 Hz, 2H); 7.33 (m. 2H); 7.24 (d, ³J(H, H)=8.5 Hz, 2H); 7.03 (d, ³J (H, H)=8.0 Hz, 2H); 6.78 (d, ³J (H,H)=7.5 Hz, 2H); 6.45 (s large, 2H); 3.75 (m, 4H), 2.68 (s, 6H). NMR-¹³C126 MHz: CDCl₃) δ, ppm: 155.7; 144.1; 137.5; 136.2; 126.8; 126.7; 122.2;114.0; 105.0; 42.8; 25.0. MS (CID, NH₃): m/z=343 (MH⁺). Analysis (%) forC₂₂H₂₂N₄.0.3CH₂Cl₂: calculated C 72.80; H 6.19; N 15.23; found C 72.41;H 6.02; N 14.87. UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4 containing 150 mMNaCl (1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=254 (44,200), 341 (6,000).

8,8′-Oxydiquinoline (Compound 15)

The product has already been described in: V. M. Dziomko et al.,Yakugaku Zasshi 1951, 71, 452-455; but using a different method ofsynthesis. Caesium carbonate (156 mg; 0.48 mmol), 8-bromoquinoline (32μl; 50 mg; 0.24 mmol) and CuCl₂.2H₂O (4.1 mg; 0.024 mmol) are added to asolution under argon of 8-hydroxyquinoline (71 mg; 0.49 mmol) in 2.0 mlof dry DMF. The mixture is heated under reflux for 72 hours. Aftercooling, 5 ml of CH₂Cl₂ and 5 ml of a 0.12 M aqueous solution of EDTAdisodium salt are added. The organic phase is recovered and the aqueousphase is subsequently extracted with CH₂Cl₂ (2×5 ml). The organic phasesare combined and washed once with 5 ml of 0.12 M EDTA in H₂O then inwater. The volume is reduced under reduced pressure then the reactioncrude product is purified by silica gel chromatography, eluted with agradient of 50 to 100% of ethyl acetate in toluene (v/v) then with 100%of CH₃OH and the solvent is evaporated to recover 15, from the methanolphase, in the form of a white powder (13 mg; 0.046 mmol, yield=19%).NMR-¹H (250 MHz, CDCl₃) δ, ppm: 8.95 (dd, ³J (H, H)=4.0 Hz, ⁴J (H,H)=1.5 Hz, 2H); 8.21 (dd, ³J (H, H)=8.5 Hz, ⁴J (H, H)=1.5 Hz, 2H); 7.61(dd, ³J (H, H)=8.0 Hz, ⁴J (H, H)=1.0 Hz, 2H); 7.46 (dd, ³J (H, H)=4.0 Hzand 8.5 Hz, 2H); 7.42 (dd, ³J (H, H)=7.5 Hz and 8.0 Hz, 2H); 7.14 (dd,³J (H, H)=7.5 Hz, ⁴J (H, H)=1.0 Hz, 2H). MS (CID, NH₃): m/z=273 (MH⁺).UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]:λ nm (ε M⁻¹ cm⁻¹)=232 (53,300), 240 (42,900), 2994 (9,400), 327 (5,800,shoulder).

7-Methyloxy-8-hydroxyquinoline

It was prepared using protocols by D. Planchenault et al. Tetrahedron1995, 51, 5823-5830; D. Nobel, J. Chem. Soc., Chem. Commun. 1993,419-420 and M. Numazawa et al. J. Chem. Soc., Chem. Commun. 1983,533-534. A solution of CH₃ONa (30% by weight) in CH₃OH (17 ml, 89.30mmol) is added to a solution of 7-bromo-8-hydroxyquinoline (2.00 g; 8.93mmol), in 125 ml of DMF. The mixture is stirred for 10 minutes underargon. CuCl₂.2 H₂O (0.46 g; 2.68 mmol) is added and the reaction mixtureis heated under reflux for 20 hours. After cooling to ambienttemperature, water (100 ml) and disodium EDTA dihydrate (7.83 g; 26.80mmol) are added and the mixture is stirred for 1 hour. The solution isacidified to pH=4-5 with CH₃COOH (3 ml) and it is subsequently basifiedgently with a saturated aqueous solution of NaHCO₃. The aqueous phase isextracted with CH₂Cl₂ (3×100 ml). The combined organic phases are driedover anhydrous Na₂SO₄ and concentrated under reduced pressure. The solidobtained is purified by silica gel chromatography, eluted using agradient of CH₂Cl₂/CH₃OH/CH₃COOH (94/4/2, v/v) to CH₂Cl₂/CH₃OH (90/10,v/v). The fractions containing the product are combined and washed witha saturated aqueous solution of NaHCO₃ (3×100 ml). The organic phase isdried over anhydrous Na₂SO₄ and concentrated under reduced pressure toyield 7-methyloxy-8-hydroxyquinoline in the form of a white powder (0.65g; 3.68 mmol, yield=40%). NMR-¹H (250 MHz, CDCl₃) δ, ppm: 8.77 (dd, ³J(H, H)=4.0 Hz, ⁴J (H, H)=1.5 Hz, 1H); 8.11 (dd, ³J (H, H)=8.5 Hz, ⁴J (H,H)=1.5 Hz, 1H); 7.36 (m, 2H), 7.31 (dd, ³J (H, H)=8.5 Hz, ³J (H, H)=4.0Hz, 1H), 4.06 (s, 3H). NMR-¹³C (63 MHz, CDCl₃) δ, ppm: 148.6 (CH); 144.0(Cq); 139.7 (Cq); 138.6 (CH); 136.0 (Cq); 123.5 (CH); 119.7 (CH); 117.7(CH); 116.4 (CH); 57.3 (CH₃). MS (CID, NH₃): m/z=176 (MH⁺). Analysis (%)for C₁₀H₉NO₂.0.1 H₂O: calculated C 67.86; H 5.24; N 7.91; found C 67.82;H 5.11; N 7.95.

7-(Methyloxy)-8-[(phenylmethyl)oxy]quinoline

7-Methyloxy-8-hydroxyquinoline (1.10 g; 6.29 mmol) and K₂CO₃ (1.30 g;9.43 mmol) in 30 ml of dry acetonitrile are stirred for 10 minutes underargon. Benzyl chloride (0.87 ml, 7.54 mmol) is then added and thereaction medium is heated under reflux overnight. After returning toambient temperature, the precipitate is filtered, washed with CH₂Cl₂ andthe filtrate is concentrated under reduced pressure. The oil obtained isdissolved again in CH₂Cl₂ (50 ml) and washed in succession with anaqueous solution of NaOH 2 N (4×50 ml) and water (1×50 ml). The organicphase is dried over anhydrous Na₂SO₄ and the solvent is evaporated underreduced pressure to yield 7-methyloxy-8-[(phenylmethyl)oxy]quinoline inthe form of a brown oil (1.28 g; 4.84 mmol, yield=77%). NMR-¹H (250 MHz,CDCl₃) δ, ppm: 8.94 (dd, ³J (H, H)=4.0 Hz, ⁴J (H, H)=1.5 Hz, 1H); 8.06(dd, ³J (H, H)=8.5 Hz, ⁴J (H, H)=1.5 Hz, 1H); 7.59-7.51 (m, 3H);7.36-7.24 (m, 5H); 5.40 (s, 2H); 3.92 (s, 3H). NMR-¹³C (63 MHz, CDCl₃)δ, ppm: 151.3 (CH); 149.5 (Cq); 142.9 (Cq); 141.2 (Cq); 137.4 (Cq);135.3 (CH); 127.9 (CH); 127.4 (CH); 127.1 (CH); 123.6 (Cq); 122.9 (CH);118.5 (CH) 114.8 (CH); 75.2 (CH₂); 56.1 (CH₃). MS (CID, NH₃): m/z=266(MH⁺). Analysis (%) for C₁₇H₁₅NO₂.0.05 CHCl₃: calculated C 75.49; H5.59; N 5.16; found C 75.74; H 5.40; N 5.33.

7-(Methyloxy)-8-[(phenylmethyl)oxy]quinoline-N-oxide

7-(methyloxy)-8-[(phenylmethyl)oxy]quinoline (0.30 g; 1.13 mmol) and 77%by weight m-chloroperbenzoic acid (0.38 g; 1.69 mmol) are added insuccession to dry CH₂Cl₂ (11 ml) at 4° C. under argon. The mixture isstirred for 48 hours at ambient temperature, then CH₂Cl₂ (40 ml) isadded. The reaction medium is washed with a saturated aqueous solutionof NaHCO₃ (2×50 ml) and the solvent is evaporated under reducedpressure. The resulting oil is purified by silica gel chromatography,eluted with a CH₂Cl₂/CH₃OH (95/5, v/v) mixture to yield7-(methyloxy)-8-[(phenylmethyl)oxy]quinoline-N-oxide in the form of ayellow oil (0.18 g; 0.64 mmol, yield=58%). NMR-¹H (250 MHz, CDCl₃) δ,ppm: 8.43 (dd, ³J (H, H)=6.0 Hz, ⁴J ((H, H)=1.0 Hz, 1H); 7.68-7.58 (m,4H); 7.41-7.30 (m, 4H); 7.10 (dd, ³J (H, H)=8.5 Hz, ³J (H, H)=6.0 Hz,1H); 5.23 (s, 2H); 3.96 (s, 3H). NMR-¹³C (63 MHz, CDCl₃) δ, ppm: 138.4;128.9; 128.7; 128.2; 127.8; 127.6; 125.7; 124.9; 123.4; 119.5; 118.8;116.8; 107.7; 75.2; 57.1. MS (CID, NH₃): m/z=282 (MH⁺). Analysis (%) forC₁₇H₁₅NO₃: calculated C 72.58; H 5.37; N 4.98; found C 72.74; H 4.91; N4.87.

Dimethylbis{7-(methyloxy)8-[phenylmethyl)oxy]-2-quinolinyl}propanedioate(Compound 16′)

The protocol was established from synthesis of 1″.7-(methyloxy)-8-[(phenylmethyl)oxy]quinoline-N-oxide (0.72 g; 2.56 mmol)is dissolved in dry CH₂Cl₂ (7 ml). Dimethylmalonate (0.307 ml, 2.69mmol) and acetic anhydride (1.18 ml) are then added to said solution andthe mixture is stirred for 24 days at ambient temperature, away fromlight and protected from humidity (by means of a CaCl₂ tube). CH₃OH (20ml) is added and, after 15 hours at −20° C., a precipitate is removed bycentrifugation. The solvent from the supernatant is evaporated and thecrude reaction product is dissolved again in CH₃OH (0.5 ml) andprecipitated by adding water (3 ml). The supernatant is removed and theprecipitate is taken up in 40 ml of CH₂Cl₂ and washed in water (2×20ml). After the solvent has evaporated, the product is purified by meansof preparative thin-layer chromatography, eluted with a CH ₂Cl₂/CH₃OH(99/1, v/v) mixture. Residual impurities are removed by crystallisationin CH₃OH to yield dimethylbis{7-(methyloxy)8-[phenylmethyl)oxy]-2-quinolinyl}propanedioate in theform of white crystals (12 mg; 0.02 mmol, yield=1.5%). NMR-¹H (250 MHz,CDCl₃) δ, ppm: 7.93 (d, ³J (H, H)=8.5 Hz, 2H); 7.63 (d, ³J (H, H)=8.5Hz, 2H); 7.59 (m, 4H); 7.47 (d, ³J (H, H)=9.0 Hz, 2H); 7.40-7.28 (m,8H); 5.41 (s, 4H); 3.95 (s, 6H); 3.84 (s, 6H). NMR-¹³C (63 MHz, CDCl₃)δ, ppm: 169.3 (CH); 157.5 (Cq); 152.2 (Cq); 142.1 (Cq); 142.1 (Cq);138.2 (Cq); 135.9 (CH); 128.4 (CH); 128.2 (CH); 127.7 (Cq); 123.2 (CH);123.0 (CH) 121.1 (CH); 115.9 (CH); 75.8 (CH₂); 75.2 (Cq); 57.1 (CH₃);53.0 (CH₃). MS (CID, NH₃): m/z=659 (MH⁺). The molecule structure wasconfirmed by X-ray diffraction analysis of monocrystals obtained bycrystallisation of the product in methanol. The structure of the complexis presented in FIG. 4. The parameters of the crystal analysis are asfollows: monoclinic crystal system; P 1 21 1; a=10.2593 (9) Å, b=10.8311(10) Å, c=15.2192(14) Å, α=90°, β=97.622(5)°, γ=90°.

2,2′-(methanediyl)-bis(7-methyloxy-8-hydroxy-2-quinolinium) dichloride(Compound 16)

The protocol was established from synthesis of 1′. Dimethylbis{7-(methyloxy)8[phenylmethyl)oxy]-2-quinolinyl}propanedioate (40 mg;0.06 mmol) is heated under reflux in 37% aqueous HCl (3 ml) for 1 hour30 minutes. After cooling, the solvent is evaporated under reducedpressure. The product obtained is solubilised in CH₃OH and poured over 3ml of diethyl ether. After centrifugation, the precipitate obtained iswashed with 3 ml of diethyl ether then dried under vacuum to yield 16 inthe form of a yellow powder (28 mg; 0.06 mmol, yield=98%). NMR-¹H (250MHz, CD₃OD) δ, ppm: 8.97 (d, ³J (H, H)=7.5 Hz, 2H), 7.86 (s, 4H); 7.68(d, ³J (H, H)=8.0 Hz, 2H); 4.16 (s, 6H). MS (DCI, NH₃): m/z=363 (MH⁺).UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]:λ nm (ε M⁻¹ cm⁻¹)=203 (47,800), 246 (34,100, shoulder), 257 (49,800),334 (3,500).

7-bromo-2-methyl-8-hydroxyquinoline

The protocol was established from works by: D. E. Pearson et al. J. Org.Chem. 1967, 2358-2360. tert-butylamine (3.23 ml, 30.78 mmol) is stirredunder argon in 100 ml of toluene for 2 hours at ambient temperature inthe presence of an activated 4 Å molecular sieve (10 g). After coolingto −70° C., N-bromosuccinimide (5.48 g; 30.78 mmol) and2-methyl-8-hydroxyquinoline (5.00 g; 30.78 mmol) are added insuccession. The mixture is slowly brought to ambient temperature(approximately 4 hours). The reaction medium is filtered and themolecular sieve is washed with diethyl ether (20 ml). The filtrate iswashed in water (3×50 ml), dried over anhydrous Na₂SO₄ and the organicphase is concentrated to yield a solid which is brought to reflux in 100ml of hexane for 1 hour. After 24 hours at ambient temperature, theprecipitate is filtered and dried under vacuum to yield7-bromo-2-methyl-8-hydroxyquinoline in the form of a white powder (4.85g; 20.47 mmol, yield=67%). NMR-¹H (250 MHz, CDCl₃) δ, ppm: 8.00 (d, ³J(H, H)=8.5 Hz, 1H); 7.52 (d, ³J (H, H)=9.0 Hz, 1H); 7.31 (d, ³J (H,H)=8.5 Hz, 1H); 7.16 (d, ³J (H, H)=9.0 Hz, 1H); 2.72 (s, 3H). NMR-¹³C(63 MHz, CDCl₃) δ, ppm: 157.9; 149.2; 137.7; 136.2; 130.1; 125.4; 122.9;118.2; 103.9; 24.8. MS (CID, NH₃): m/z=238 (MH⁺). Analysis (%) forC₁₀H₈BrNO: calculated C 50.45; H 3.39; N 5.88; found C 50.02; H 3.37; N6.12.

2-methyl-7-(methyloxy)-8-quinolinol

The protocol was established using works by: D. Planchenault et al.Tetrahedron 1995, 51, 5823-5830. A solution of CH₃ONa (30% by weight) inCH₃OH (8.04 ml; 42.2 mmol) is added to a solution of7-bromo-2-methyl-8-hydroxyquinoline (1.00 g; 4.22 mmol) in DMF (60 ml).The mixture is stirred for 10 minutes under argon. CuCl₂.2H₂O (0.22 g;1.27 mmol) is added and the reaction mixture is heated under reflux for30 hours. After cooling, water (50 ml) and disodium EDTA dihydrate (10g; 27 mmol) are added and the medium is stirred for 1 hour. The solutionis lightly acidified with acetic acid (3 ml, pH=4-5) and subsequentlyrebasified gently with a saturated aqueous solution of NaHCO₃ (3 ml).The aqueous phase is extracted with CH₂Cl₂ (3×100 ml). The combinedorganic phases are dried over anhydrous Na₂SO₄ and concentrated underreduced pressure. The solid obtained is purified by silica gelchromatography, eluted using a gradient of CH₂Cl₂/CH₃OH/CH₃COOH (94/4/2,v/v) to CH₂Cl₂/CH₃OH/CH₃COOH (94/5/1, v/v) then to CH₂Cl₂/CH₃OH (94/6,v/v). Fractions containing the product are combined and washed with asaturated aqueous solution of NaHCO₃ (3×100 ml). The organic phase isdried over anhydrous Na₂SO₄ and concentrated under reduced pressure toyield 2-methyl-7-(methyloxy)-8-quinolinol in the form of a white powder(480 mg; 2.54 mmol, yield=60%). NMR-¹H (250 MHz, CDCl₃) δ, ppm: 7.95 (d,³J (H, H)=8.5 Hz, 1H); 7.26 (s, 2H); 7.15 (d, ³J (H, H)=8.5 Hz, 1H);4.03 (s, 3H); 2.69 (s, 3H). NMR-¹³C (63 MHz, CDCl₃) δ, ppm: 157.6 (Cq);143.9 (Cq); 139.3 (Cq); 138.0 (Cq); 136.0 (CH); 121.7(Cq); 120.6 (CH);117.3 (CH); 115.2 (CH); 57.2 (CH₃); 25.1 (CH₃). MS (CID, NH₃): m/z=190(MH⁺). Analysis (%) for C₁₁H₁₁NO₂: calculated C 69.83; H 5.86; N 7.40;found C 69.40; H 5.85; N 7.47.

2,2′-(1,2-ethanediyl)-bis[7-(methyloxy)-8-quinolinol] (Compound 17)

The protocol was established from synthesis of 7′.2-methyl-7-(methyloxy)-8-quinolinol (0.50 g, 2.64 mmol) is stirred underargon in 10 ml of distilled THF for 30 minutes at ambient temperature inthe presence of an activated 4 A molecular sieve (2.0 g). After coolingto −90° C., a 1.5 M solution of LDA-THF in cyclohexane (3.70 ml, 5.56mmol) is added dropwise over a 10-minute period. The mixture issubsequently slowly brought to −50° C., then cooled again to −90° C.1,2-dibromoethane (0.50 ml; 5.82 mmol) is added and the mixture isbrought to ambient temperature in the presence of the cold bath (4hours). Water (5 ml) and CH₃COOH (0.50 ml, pH=4-5) are added and themedium is stirred for 1 hour. The molecular sieve is removed byfiltration and is washed in succession with a saturated aqueous solutionof NaHCO₃ (10 ml), water (10 ml) and diethyl ether (40 ml). The biphasicfiltrate is transferred to a separating funnel and the organic phasecollected. The aqueous phase is extracted with diethyl ether (3×50 ml)and the combined organic phases are dried over anhydrous Na₂SO₄ andconcentrated under reduced pressure. The resulting solid is dissolvedhot in CH₃OH (10 ml) and the white precipitate formed is collected after3 days, yielding pure 17 after drying under vacuum (306 mg; 0.81 mmol,yield=62%). NMR-¹H (250 MHz, CDCl₃) δ, ppm: 8.00 (d, ³J (H, H)=8.5 Hz,2H); 7.28 (s, 4H); 7.24 (d, ³J (H, H)=8.5 Hz, 2H); 4.04 (s, 6H); 3.57(s, 4H). NMR-¹³C (63 MHz, CDCl₃) δ, ppm: 160.1 (Cq); 144.0 (Cq); 139.3(Cq); 137.9 (Cq); 136.3 (CH); 121.9(Cq); 120.4 (CH); 117.5 (CH); 115.5(CH); 57.2 (CH₃); 37.1 (CH₂). MS (CID, NH₃): m/z=377 (MH⁺). Analysis (%)for C₂₂H₂₀N₂O₄.0.2 H₂O: calculated C 69.53; H 5.41; N 7.37; found C69.40; H 5.30; N 7.47. UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4 containing150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=204 (83,000), 208 (53,200,shoulder), 252 (97,200), 338 (6,600).

8-hydroxy-N-(8-hydroxy-2-quinolinyl)-2-quinolinecarboxamide (Compound18)

1-hydroxybenzotriazole monohydrate (71 mg; 0.53 mmol),(benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate(177 mg; 0.40 mmol) and triethylamine (0.037 ml; 0.26 mmol) are added toa suspension of 8-hydroxyquinoline-2-carboxylic acid (50 mg; 0.26 mmol)in 5 ml of CH₂Cl₂. The mixture is stirred for 30 minutes at ambienttemperature, then 2-amine-8-hydroxyquinoline (85 mg; 0.53 mmol) andtriethylamine (0.037 ml; 0.26 mmol then, after stirring for 5 minutes,0.117 ml; 0.794 mmol) are added. The mixture is stirred for 18 hours atambient temperature, then 10 ml of H₂O and 5 ml of CH₂Cl₂ are added andthe organic phase is recovered by decantation. The volume is reduced byevaporation under reduced pressure then the product is purified bysilica gel chromatography, eluted with a CH₂Cl₂/CH₃OH (995/0.5, v/v)mixture and the solvent is evaporated under reduced pressure. Theproduct is dissolved in 30 ml of CH₂Cl₂ and 30 ml of a saturated aqueoussolution of NaHCO₃ are added. The product is extracted 3 times withCH₂Cl₂ then the organic phases are combined and the solvent isevaporated under reduced pressure to yield 18 in the form of a whitepowder (28 mg; 0.085 mmol, yield=32%). NMR-¹H (250 MHz, DMSO-d6) δ, ppm:11.89 (s, 1H); 10.89 (s, 1H); 9.55 (s, 1H); 8.60 (d, ³J (H, H)=8.5 Hz,1H); 8.41 (s, 2H); 8.32 (d, ³J (H, H)=8.5 Hz, 1H); 7.63 (dd, ³J (H,H)=7.0 and 8.0 Hz, 1H); 7.53 (dd, ³J (H, H)=8.0 Hz, ⁴J (H, H)=1.0 Hz,1H); 7.42 (dd, ³J (H, H)=8.0 Hz, ⁴J (H, H)=2.0 Hz, 1H); 7.37 (dd, ³J (H,H)=7.0 and 8.0 Hz, 1H); 7.23 (dd, ³J (H, H)=7.0 Hz, ⁴J (H, H)=1.0 Hz,1H); 7.13 (dd, ³J (H, H)=7.0 Hz, ⁴J (H, H)=2.0 Hz, 1H). MS (CID, NH₃):m/z=332 (MH⁺). UV/vis [DMSO/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl(1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=259 (49,100), 332 (11,200, shoulder).

2-{[8-hydroxy-2-quinolinyl)amino]methyl}-8-quinolinol (Compound 19)

A solution of 2-amino-8-hydroxyquinoline (100 mg; 0.62 mmol) and8-hydroxyquinoline-2-carboxaldehyde (130 mg; 0.75 mmol) in 8 ml of1,2-dichloroethane is stirred for 1 hour at ambient temperature then(CH₃COO)₃BHNa (291 mg; 1.29 mmol) is added and stirring is continued for90 minutes at ambient temperature. 50 ml of CH₂Cl₂ and 50 ml of asaturated aqueous solution of NaHCO₃ are then added. The organic phaseis recovered then the aqueous phase is extracted with CH₂Cl₂ (2×120 ml).The organic phases are combined and dried over anhydrous Na₂SO₄, thenthe solvent is evaporated. The product is dissolved in 75 ml of CH₂Cl₂and precipitated by adding a volume (75 ml) of hexane. The supernatantis recovered by filtration and the solvent is evaporated. Theevaporation residue is purified by silica gel chromatography, elutedusing a CH₂Cl₂/CH₃OH mixture (0.5 to 1% of CH₃OH; v/v) to yield afterevaporation of the solvent 19 in the form of a beige powder (32 mg; 0.10mmol; yield=16%). NMR-¹H (200 MHz, DMSO-d₆) δ, ppm: 9.79 (s, 1H); 8.55(s, 1H); 8.29 (d, ³J (H, H)=8.5 Hz, 1H); 8.01 (t, ³J (H, H)=4.5 Hz, 1H);7.93 (d, ³J (H, H)=9.0 Hz, 1H); 7.57 (d, ³J (H, H)=8.5 Hz, 1H); 7.39 (m,2H); 7.08 (m, 4H); 6. 91 (dd, ³J (H, H)=8.0 Hz, ⁴J (H, H)=1.5 Hz, 1H);5.08 (d, ³J (H, H)=4.5 Hz, 2H). MS (FAB, MBA): m/z=318 (MH⁺).

2,2′-(iminodimethanediyl)di(N-boc-8-quinolinyl amine) (Compound 20′)

0.25 ml of a 7 M solution of NH₃ (1.75 mmol) in CH₃OH is added to asolution of 1,1-dimethyl(2-formyl-8-quinolinyl)carbamate (300 mg; 1.10mmol) in 15 ml of 1,2-dichloroethane, and the mixture is stirred for 30minutes at ambient temperature. (CH₃COO)₃BHNa (432 mg; 2.04 mmol) isadded and stirring is continued for 15 hours at ambient temperature,then the solvent is evaporated under reduced pressure. The product ispurified by silica gel chromatography, eluted with ethyl acetate toyield after evaporation of the solvent2,2′-(iminodimethanediyl)di(N-boc-8-quinolinyl amine) in the form of apale yellow powder (150 mg; 0.28 mmol, yield=52%). NMR-¹H (200 MHz,CDCl₃) δ, ppm: 8.98 (s large, 2H); 8.41 (d large, ³J (H, H)=7.0 Hz, 2H);8.10 (d, ³J (H, H)=8.5 Hz, 2H); 7.53 (d, ³J (H, H)=8.5 Hz, 2H); 7.48(dd, ³J (H, H)=8.0 and 7.5 Hz, 2H); 7.40 (dd, ³J (H, H)=8.0 Hz, ⁴J (H,H)=1.5 Hz, 2H); 4.25 (s, 4H); 2.21 (s large, 1H); 1.53 (s, 18H). NMR-¹³C(50 MHz, CDCl₃) δ, ppm: 157.7 (Cq); 152.9 (Cq); 137.4 (Cq); 136.8 (CH);134.8 (Cq); 127.1 (Cq); 126.9 (CH); 120.9 (CH); 120.0 (CH); 114.7 (CH);80.4 (Cq); 54.9 (CH₂); 28.3 (CH₃). MS (CID, NH₃): m/z=530 (MH⁺).Analysis (%) for C₃₀H₃₅N₅O₄.0.25 C₄H₈O₂: calculated C 67.16; H 6.77; N12.71; found C 67.59; H 7.10; N 12.23.

2,2′-(iminodimethanediyl)di(8-quinolinyl amine) (Compound 20)

A solution of 2,2′-(iminodimethanediyl)di(N-boc-8-quinolinyl amine) (100mg; 0.19 mmol) in 2.5 ml of CH₂Cl₂ and 2.5 ml trifluoroacetic acid isstirred for 45 minutes at ambient temperature then the solvents areevaporated under reduced pressure. Diethyl ether (10 ml) is added andthe solvent is again evaporated. The product is taken up in 20 ml ofCH₂Cl₂ and washed with a saturated aqueous solution of NaHCO₃ (2×40 ml).The organic phase is dried over anhydrous Na₂SO₄ then the solvent isevaporated under reduced pressure to yield 20 in the form of a beigepowder (62 mg; 0.19 mmol, quantitative yield). NMR-¹H (250 MHz, CDCl₃)δ, ppm: 8.01 (d, ³J(H, H)=8.5 Hz, 2H); 7.40 (d, ³JH, H)=8.5 Hz, 2H);7.29 (dd, ³J (H, H)=8.0 and 8.0 Hz, 2H); 7.13 (dd, ³J (H, H)=8.0, ⁴J (H,H)=1.0 Hz, 2H); 6.91 (d large, ³J (H, H)=8.0 Hz, 2H); 5.01 (s large,4H); 4.22 (s, 4H); 2.60 (s large, 1H). NMR-¹³C (50 MHz, CDCl₃) δ, ppm:157.0 (Cq); 143.6 (Cq); 137.6 (Cq); 136.4 (CH); 127.7 (Cq); 126.8 (CH);120.8 (CH); 115.9 (CH); 110.2 (CH); 54.9 (CH₂). MS (CID, NH₃): m/z=330(MH⁺).

2,2′,2″-(nitrilotrimethanediyl)tri(N-boc-8-quinoline amine) (Compound21′)

30 μl of a 7 M solution of NH₃ (0.21 mmol) in CH₃OH is added to asolution of 1,1-dimethyl(2-formyl-8-quinolinyl)carbamate (50 mg; 0.18mmol) in 2.5 ml of 1,2-dichloroethane, and the mixture is stirred for 5minutes at ambient temperature. (CH₃COO)₃BHNa (72 mg; 0.34 mmol) isadded and stirring is continued for 15 hours at ambient temperature. 10ml of CH₂Cl₂ and 10 ml of a saturated aqueous solution of NaHCO₃ arethen added, the organic phase is recovered then the aqueous phase isextracted with CH₂Cl₂ (2×10 ml). The organic phases are combined anddried over anhydrous Na₂SO₄, then the solvent is evaporated underreduced pressure. The product is purified by silica gel chromatography,eluted with CH₂Cl₂ to yield after evaporation of the solvent2,2′,2″-(nitrilotrimethanediyl)tri(N-boc-8-quinoline amine) in the formof a pale yellow powder (25 mg; 0.032 mmol, yield=52%). NMR-¹H (250 MHz,CDCl₃) δ, ppm: 9.03 (s, 3H); 8.39 (d large, ³J (H, H)=7.5 Hz, 3H); 8.11(d, ³J (H, H)=8.5 Hz, 3H); 7.75 (d, ³J (H, H)=8.5 Hz, 3H); 7.47 (dd, ³J(H, H)=8.0 and 7.5 Hz, 3H); 7.38 (dd, ³J (H, H)=8.0 Hz, ⁴J (H, H)=1.5Hz, 3H); 4.10 (s, 6H); 1.59 (s, 27H). NMR-¹³C (63 MHz, CDCl₃) δ, ppm:157.8 (Cq); 152.9 (Cq); 137.3 (Cq); 136.7 (CH); 134.9 (Cq); 127.1 (Cq);127.0 (CH); 121.4 (CH); 119.9 (CH); 114.6 (CH); 80.5 (Cq); 61.0 (CH₂);28.4 (CH₃). MS (CID, NH₃): m/z=786 (MH⁺).

2,2′,2″-(nitrilotrimethanediyl)tri(8-quinoline amine) (Compound 21)

A solution of 2,2′,2″-(nitrilotrimethanediyl)tri(N-boc-8-quinolineamine) (10 mg; 0.013 mmol) in 0.5 ml of CH₂Cl₂ and 0.5 ml oftifluoroacetic acid is stirred for 45 minutes at ambient temperaturethen the solvents are evaporated under reduced pressure. Diethyl ether(5 ml) is added and the solvent is again evaporated under reducedpressure. The product is taken up in 15 ml of CH₂Cl₂ and washed with asaturated aqueous solution of NaHCO₃ (2×10 ml). The organic phase isdried over anhydrous Na₂SO₄ then solvent is evaporated under reducedpressure to yield 21 in the form of a beige powder (6 mg; 0.013 mmol,quantitative yield). NMR-¹H (250 MHz, CDCl₃) δ, ppm: 8.05 (d, ³J(H,H)=8.5 Hz, 3H); 7.67 (d, large, ³J (H, H)=8.5 Hz, 3H); 7.29 (dd, ³J (H,H)=8.0 and 7.0 Hz, 3H); 7.12 (dd, ³J (H, H)=8.5 Hz, ⁴J (H, H)=1.0 Hz,3H); 6.90 (d large, ³J (H, H)=7.0 Hz, 3H); 4.99 (s large, 6H); 4.08 (slarge, 6H). MS (CID, NH₃): m/z=486 (MH⁺).

[2-(butylamino)methyl]-N-boc-8-quinoline amine

The protocol was inspired by the works of G. Xue et al., Tetrahedron2001, 57, 7623-7628, on other products. 1-butylamine (40 μl; 0.40 mmol)is added to a solution under argon of1,1-dimethyl(2-formyl-8-quinolinyl)carbamate (50 mg; 0.18 mmol) in 2.5ml of 1,2-dichloroethane and the mixture is stirred for 30 minutes atambient temperature then (CH₃COO)₃BHNa (72 mg; 0.34 mmol) is added andstirring is continued for 15 hours at ambient temperature. 10 ml ofCH₂Cl₂ and 10 ml of a saturated aqueous solution of NaHCO₃ are thenadded, the organic phase is recovered then the aqueous phase isextracted with CH₂Cl₂ (2×10 ml). The organic phases are combined anddried over anhydrous Na₂SO₄, then the solvent is evaporated underreduced pressure to yield [2-(butylamino)methyl]-N-boc-8-quinoline aminein the form of an orange oil (39 mg; 0.12 mmol, yield=65%). NMR-¹H (250MHz, CDCl₃) δ, ppm: 9.00 (s large, 1H); 8.39 (d large, ³J (H, H)=7.0 Hz,1H); 8.08 (d, ³J (H, H)=8.5 Hz, 1H); 7.46 (dd, ³J (H, H)=8.5 and 7.0 Hz,1H); 7.41 (dd, ³J (H, H)=8.5 Hz, ⁴J (H, H)=2.0 Hz, 1H); 7.39 (dd, ³J (H,H)=8.5 Hz, ⁴J (H, H)=1.5 Hz, 1H); 4.10 (s, 1H); 2.73 (t, ³J (H, H)=7.5Hz, 2H); 2.13 (s large, 1H); 1.59 (s, 9H); 1.56 (m, 2H); 1.40 (m, 2H);0.94 (t, ³J (H, H)=7.0 Hz, 3H).

2,2′-[(butylimino)dimethanediyl]di(N-boc-8-quinoline amine) (Compound22′)

A solution of [2-(butylamino)methyl]-N-boc-8-quinoline amine (39 mg;0.12 mmol) and 1,1-dimethyl(2-formyl-8-quinolinyl)carbamate (36 mg; 0.13mmol) in 2.5 ml of 1,2-dichloroethane is stirred for 30 minutes atambient temperature then (CH₃COO)3BHNa (35 mg; 0.16 mmol) is added andstirring is continued for 20 hours at ambient temperature. 10 ml ofCH₂Cl₂ and 10 ml of a saturated aqueous solution of NaHCO₃ are thenadded, the organic phase is recovered then the aqueous phase isextracted with CH₂Cl₂ (2×10 ml). The organic phases are combined anddried over anhydrous Na₂SO₄, then the solvent is evaporated underreduced pressure to yield2,2′-[(butylimino)dimethanediyl]di(N-boc-8-quinoline amine) in the formof a pale yellow powder which is characterised by NMR-¹H then introducedinto the subsequent reaction without additional purification. NMR-¹H(250 MHz, CDCl₃) δ, ppm: 9.02 (s large, 2H); 8.38 (d large, ³J (H,H)=7.5 Hz, 2H); 8.09 (d, ³J (H, H)=8.5 Hz, 2H); 7.72 (d, ³J (H, H)=8.5Hz, 2H); 7.46 (dd, ³J (H, H)=8.0 and 7.5 Hz, 2H); 7.38 (dd, ³J (H,H)=8.0 Hz, ⁴J (H, H)=1.5 Hz, 2H); 3.99 (s, 4H); 2.62 (t, ³J (H, H)=7.0Hz, 2H); 1.62 (m, 2H); 1.59 (s, 18H); 1.34 (m, 2H); 0.87 (t, ³J (H,H)=7.5 Hz, 3H).

2,2′-[(butylimino)dimethanediyl]di(8-quinoline amine) (Compound 22)

2,2′-[(butylimino)dimethanediyl]di(N-boc-8-quinoline amine) obtained inthe previous stage is dissolved in 0.5 ml of CH₂Cl₂ and 0.5 ml oftrifluoroacetic acid and stirred for 45 minutes at ambient temperature,then the solvents are evaporated under reduced pressure. The residue isdissolved in 5 ml of CH₂Cl₂ and washed with a saturated aqueous solutionof NaHCO₃ (2×5 ml) before being dried over anhydrous Na₂SO₄, then thesolvent is evaporated under reduced pressure. The product is purified bysilica gel chromatography, eluted with a hexane/ethyl acetate mixture(8/2 to 1/1; v/v) to yield after evaporation of the solvent 22 in theform of an orange oil (20 mg; 0.05 mmol, yield=42% over 2 stages).NMR-¹H (250 MHz, CDCl₃) δ, ppm: 8.02 (d, ³J (H, H)=8.5 Hz, 2H); 7.65 (d,³J (H, H)=8.5 Hz, 2H); 7.28 (dd, ³J (H, H)=8.5 and 7.5 Hz, 2H); 7.12(dd, ³J (H, H)=8.5 Hz, ⁴J (H, H)=1.0 Hz, 2H); 6.90 (dd, ³J (H, H)=7.5Hz, ⁴J (H, H)=1.0 Hz, 2H); 4.98 (s large, 4H); 3.97 (s, 4H); 2.60 (t, ³J(H, H)=7.0 Hz, 2H); 1.60 (tt, ³J (H, H)=7.5 and 7.0 Hz, 2H); 1.32 (qt,³J (H, H)=8.0 and 7.5 Hz, 2H); 0.85 (t, ³J (H, H)=8.0 Hz, 3H). NMR-¹³C(63 MHz, CDCl₃) δ, ppm: 143.7 (Cq); 137.4 (Cq); 136.2 (CH); 127.7 (Cq);126.8 (CH); 126.7 (Cq); 121.3 (CH); 115.8 (CH); 110.0 (CH); 60.9 (CH₂);54.3 (CH₂); 29.4 (CH₂); 20.5 (CH₂); 13.9 (CH₃). MS (CID, NH₃): m/z=386(MH⁺).

2-Chloro-8-nitroquinoline

Synthesis was carried out according to the protocol of: M. C. Kimber etal., Aust. J. Chem 2003, 56, 39-44. NMR data which are more specificthan those previously published are added hereinafter. NMR ¹H (250 MHz,CDCl₃) δ, ppm: 8.21 (d, ³J (H, H)=8.5 Hz, 1H); 8.10 (dd, ³J (H, H)=7.5Hz, ⁴J (H, H)=1.5 Hz, 1H); 8.05 (dd, ³J (H, H)=8.0 Hz, ⁴J (H, H)=1.5 Hz,1H); 7.65 (m, 1H); 7.55 (d, ³J (H, H)=8.5 Hz, 1H). NMR-¹³C (63 MHz,CDCl₃) δ, ppm: 153.5 (Cq); 147.1 (Cq); 138.9 (Cq); 138.8 (CH); 131.9(CH); 127.6 (Cq); 125.8 (CH); 125.0 (CH); 124.5 (CH). MS (CID, NH₃):m/z=209 (MH⁺), 226 (MNH₄ ⁺), 243 (MN₂H₇ ⁺). Analysis (%) for C₉H₅N₂O₂Cl:calculated C 51.82; H 2.42; N 13.43; found C 51.76; H 2.37; N 13.24. Themolecule structure was confirmed by X-ray diffraction analysis onmonocrystals obtained by crystallisation of the product in deuteratedchloroform. The structure is presented in FIG. 5. The parameters forcrystal analysis are as follows: orthorhombic crystal system; P c a 21;a=18.090 (4) Å, b=3.7781 (7) Å, c=12.581 (2) Å, α=90°, β=90°, γ=90°.

N-butyl-8-nitro-2-quinoline amine

2-chloro-8-nitroquinoline (0.20 g; 0.96 mmol) is suspended in 9.5 ml of1-butylamine and the medium is heated under reflux (78° C.) for 15hours. The yellow solution obtained is subsequently concentrated undervacuum. The crude reaction product is taken up in a minimum volume ofCH₃OH and poured over 3 ml of diethyl ether. After centrifugation, butylammonium chloride crystals are removed and the supernatant isconcentrated under reduced pressure to yield N-butyl-8-nitro-2-quinolineamine in the form of a yellow oil (0.21 g; 0.86 mmol, yield=90%) NMR-¹H(250 MHz, CDCl₃) δ, ppm: 7.83 (dd, ³J (H, H)=7.5 Hz, ⁴J (H, H)=1.5 Hz,1H); 7.77 (d, ³J (H, H)=9.0 Hz, 1H); 7.69 (dd, ³J (H, H)=8.0 Hz, ⁴J (H,H)=1.5 Hz, 1H); 7.14 (m, 1H), 6.67 (d, ³J (H, H)=9.0 Hz, 1H); 5.07 (slarge, 1H); 3.47 (m, 2H); 1.60 (m, 2H); 1.39 (m, 2H); 0.93 (t, ³J (H,H)=7.5 Hz, 3H). NMR-¹³C (63 MHz, CDCl₃) δ, ppm: 157.8 (Cq); 145.6 (Cq);140.2 (Cq); 136.7 (CH); 131.5 (CH); 124.7 (CH); 124.1 (CH); 119.7 (CH);113.3 (Cq); 41.3 (CH₂); 31.5 (CH₂); 20.2 (CH₂); 13.8 (CH₃). MS (CID,NH₃): m/z=246 (MH⁺). Analysis (%) for C₁₃H₁₅N₃O₂: calculated C 63.66; H6.16; N 17.13; found C 63.33; H 6.21; N 16.64.

N-butyl-2,2′-imino-bis(8-nitroquinoline) (Compound 23′)

2-chloro-8-nitroquinoline (122 mg; 0.59 mmol) and NaOtBu (77.5 mg; 0.81mmol) are added to a violet suspension of N-butyl-8-nitro-2-quinolineamine (0.17 g; 0.69 mmol), tris(dibenzylidene-acetone)-dipalladium(0)(13 mg; 0.014 mmol) and rac-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl(17 mg; 0.027 mmol) in 5 ml of toluene under argon. The medium is heatedunder reflux for 3 hours, then 2-chloro-8-nitroquinoline (22 mg; 0.11mmol) is again added. Heating is continued for 2 hours 30 minutes then10 ml of a saturated ammonium chloride solution are added. The productis extracted with 3×30 ml of CH₂Cl₂ and the solvent is evaporated underreduced pressure. The product is purified by silica gel chromatography,eluted with CH₂Cl₂/hexane (80/20, v/v) to yieldN-butyl-2,2′-imino-bis(8-nitroquinoline) in the form of a yellow powder(0.11 g; 0,26 mmol, yield=38%). NMR-¹H (250 MHz, CDCl₃) δ, ppm: 8.14 (d,³J (H, H)=9.0 Hz, 2H); 7.99 (dd, ³J (H, H)=7.5 Hz, ⁴J (H, H)=1.5 Hz,2H); 7.93 (dd, ³J (H, H)=8.0 Hz, ⁴J (H, H)=1.5 Hz, 2H); 7.73 (d, ³J (H,H)=9.0 Hz, 2H); 7.43 (m, 2H); 4.45 (t, ³J (H, H)=7.5 Hz, 2H); 1.83 (m,2H); 1.47 (m, 2H); 0.98 (t, ³J (H, H)=7.5 Hz, 3H). NMR-¹³C (63 MHz,CDCl₃) δ, ppm: 156.2 (Cq); 146.4 (Cq); 138.7 (Cq); 137.0 (CH); 131.5(CH); 126.2 (Cq); 124.2 (CH); 122.8 (CH); 117.3 (CH); 48.9 (CH₂); 30.4(CH₂); 20.3 (CH₂); 13.9 (CH₃). MS (CID, NH₃): m/z=418 (MH⁺). Analysis(%) for C₂₂H₁₉N₅O₄: calculated C 63.30; H 4.59; N 16.78; found C 63.18;H 4.49; N 16.39. UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4 containing 150 mMNaCl (1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=210 (91,400), 226 (53,500,shoulder), 270 (42,100), 294 (26,700, shoulder), 383 (28,400).

N-butyl-2,2′-imino-bis(8-quinoline amine) (Compound 23)

10% by weight palladium on carbon (50 mg) is added to a solution ofN-butyl-2,2′-imino-bis(8-nitroquinoline) (230 mg; 0.55 mmol) in 35 ml ofethyl acetate. The mixture is placed under a dihydrogen atmosphere (1bar) and stirred for 4 hours at ambient temperature. After the palladiumhas been removed by filtration over cellite, the organic phase isconcentrated under reduced pressure. The crude reaction product is takenup in the minimum amount of CH₂Cl₂ and precipitated with four volumes ofhexane. After filtration, the supernatant is concentrated under reducedpressure and the product is dried under vacuum to yield 23 in the formof a brown powder (197 mg; 0.55 mmol, quantitative yield). NMR-¹H (250MHz, CDCl₃) δ, ppm: 7.90 (d, ³J (H, H)=9.0 Hz, 2H); 7.32 (d, ³J (H,H)=9.0 Hz, 2H); 7.20 (m, 2H); 7.10 (dd, ³J (H, H)=8.0 Hz, ⁴J (H, H)=1.0Hz, 2H); 6.93 (dd, ³J (H, H)=7.5 Hz, ⁴J (H, H)=1.0 Hz, 2H); 4.60 (s,4H); 4.48 (t, ³J (H, H)=7.5 Hz, 2H); 1.88 (m, 2H); 1.47 (m, 2H); 0.97(t, ³J (H, H)=7.5 Hz, 3H). NMR-¹³C (63 MHz, CDCl₃) δ, ppm: 154.1 (Cq);142.1 (Cq); 137.2 (CH); 137.0 (Cq); 125.3 (Cq); 125.0 (CH); 116.3 (CH);116.1 (CH); 111.3 (CH); 48.9 (CH₂); 30.6 (CH₂); 20.7 (CH₂); 14.1 (CH₃).MS (CID, NH₃): m/z=358 (MH⁺). UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=211 (53,400,shoulder), 302 (40,300), 367 (20,000), 382 (14,600, shoulder).

N-8-quinolinyl-8-quinoline carboxamide (Compound 24)

(Benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate(192 mg; 0.43 mmol), 1-hydroxybenzotriazole monohydrate (79 mg; 0.59mmol) and triethylamine (0.200 ml; 1.44 mmol) are added to a solution ofquinoline-8-carboxylic acid (50 mg; 0.29 mmol) dissolved in 5 ml of dryCH₂Cl₂. After stirring for 30 minutes at ambient temperature,8-aminoquinoline (84 mg; 0.58 mmol) is added and the mixture is stirredfor 4 hours 30 minutes at ambient temperature. Water (10 ml) is addedand the product is extracted with CH₂Cl₂ (3×10 ml). The volume isreduced and the product is purified by silica gel chromatography, elutedwith CH₂Cl₂/CH₃OH (0 to 2%, v/v) then the solvent is evaporated underreduced pressure and the fractions containing a high proportion ofproducts are repurified by silica gel chromatography, eluted withCH₂Cl₂/CH₃OH (99.5/0.5; v/v). 24 is obtained after evaporation of thesolvent in the form of a white powder (83 mg; 0.28 mmol, yield=96%).NMR-¹H (250 MHz, CDCl₃) δ, ppm: 15.13 (s, 1H); 9.25 (dd, ³J (H, H)=4.0Hz, ⁴J (H, H)=2.0 Hz, 1H); 9.19 (dd, ³J (H, H)=7.5 Hz, ⁴J (H, H)=1.5 Hz,1H); 9.00 (m, 2H); 8.32 (dd, ³J (H, H)=8.0 Hz, ⁴J (H, H)=2.0 Hz, 1H);8.19 (dd, ³J (H, H)=8.0 Hz, ⁴J (H, H)=1.5 Hz, 1H); 8.01 (dd, ³J (H,H)=8.0 Hz, ⁴J (H, H)=1.5 Hz, 1H); 7.74 (dd, ³J (H, H)=7.5 and 8.0 Hz,1H); 7.60 (m, 3H); 7.48 (dd, ³J (H, H)=4.5 and 8.0 Hz, 1H). NMR-¹³C (63MHz, CDCl₃) δ, ppm:; 164.28; 149.48; 148.57; 145.60; 140.12; 137.59;136.65; 136.18; 134.02; 132.10; 129.85; 128.41; 128.28; 127.50; 126.63;121.75; 121.34; 121.12; 118.18. MS (CID, NH₃): m/z=300 (MH⁺). UV/vis[DMSO/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl (8/2, v/v)]: λ nm (εM⁻¹ cm⁻¹)=261 (13,300, shoulder), 274 (14,800), 294 (12,200).

N-8-quinolinyl-8-quinolinesulfonamide (Compound 25)

The product has already been described in: V. M. Dziomko et al.,Azotsoderzhashchie Geterotsikly 1967, 281-284; but by a different methodof synthesis. Several grains of activated 4 Å molecular sieve are addedto a solution under argon of 8-aminoquinoline (200 mg; 1.39 mmol) andtriethylamine (0.30 ml; 2.15 mmol) in 10 ml of CHCl₃ and the mixture isstirred slowly for 1 hour. 8-quinolinesulfonyl chloride (350 mg; 1.54mmol) is added and the mixture is heated to 65° C. for 15 hours. Aftercooling, 50 ml of CHCl₃ are added and the mixture is washed in water(2×50 ml) then dried over anhydrous Na₂SO₄ and the solvent is evaporatedunder reduced pressure. The solid is washed with 5 ml of CH₂Cl₂ to yieldafter drying 25 in the form of a beige powder (108 mg; 0.32 mmol,yield=23%) NMR-¹H (250 MHz, DMSO-d₆) δ, ppm: 10.44 (s, 1H); 9.11 (dd, ³J(H, H)=4.5 Hz, ⁴J (H, H)=1.5 Hz, 1H); 8.83 (dd, ³J (H, H)=4.0 Hz, ⁴J (H,H)=1.5 Hz, 1H); 8.47 (dd, ³J (H, H)=7.5 Hz, ⁴J (H, H)=1.5 Hz, 1H); 8.40(dd, ³J (H, H)=8.5 Hz, ⁴J (H, H)=1.5 Hz, 1H); 8.22 (dd, ³J (H, H)=8.0Hz, ⁴J (H, H)=1.5 Hz, 1H); 8.20 (dd, ³J (H, H)=8.0 Hz, ⁴J (H, H)=1.5 Hz,1H); 7.80 (dd, ³J (H, H)=7.5 Hz, ⁴J (H, H)=1.5 Hz, 1H); 7.70 (dd, ³J (H,H)=8.0 and 7.5 Hz, 1H); 7.62 (dd, ³J (H, H)=8.5 and 4.5 Hz, 1H); 7.51((dd, ³J (H, H)=8.5 and 4.0 Hz, 1H); 7.50 (dd, ³J (H, H)=8.5 Hz, ⁴J (H,H)=1.0 Hz, 1H); 7.42 (dd, ³J (H, H)=8.0 and 7.5 Hz, 1H). NMR-¹³C (63MHz, DMSO-d₆) δ, ppm: 151.5 (CH); 148.9 (CH); 142.1 (Cq); 137.6 (Cq);136.9 (CH); 136.3 (CH); 134.4 (CH); 134.2 (Cq); 133.7 (Cq); 131.7 (CH);128.2 (Cq); 127.8 (Cq); 126.6 (CH); 125.5 (CH); 122.6 (CH); 122.3 (CH);122.1 (CH); 113.8 (CH). MS (CID, NH₃): m/z=336 (MH⁺). Analysis (%) forC₁₈H₁₃N₃O₂S.0.2 H₂O: calculated C 63.78; H 3.98; N 12.40; found C 63.53;H 3.70; N 12.23.

Results:

Capacity of Compounds to Chelate Metals:

Determination of the Metal/Ligand Stoichiometry:

UV-visible absorption spectra and UV-visible spectrophotometrictitrations were carried out in the presence of a 20 mM Tris-HCl bufferpH=7.4 containing 150 mM NaCl since this is the solvent used for theAβ₁₋₄₂ resolubilisation experiments. An organic solvent (CH₃OH, dioxaneor DMSO) was added in order to achieve good solubility of the ligandsand metal complexes in the concentrations used in these experiments.Exact proportions of the organic solvent/buffer mixture are specifiedfor each UV-visible characterisation of the different ligands or metalcomplexes.

Aliquot portions of concentrated CuCl₂ or ZnCl₂ solutions (M) are addedto a 15 μM ligand solution so as to induce only negligible variations involume. After each addition, changes in absorption spectra are observedimmediately and are consistent between two additions, which correspondsto a rapid complexing process. The exact absorption values relating toeach ligand and the copper(II) or zinc(II) complexes thereof aredetailed hereinafter in the Experimental part (in the Synthesis part forligands and hereinafter for the metal complexes).

The stoichiometry of the different ligands (L) for Cu(II) or ZN(II) havetherefore been determined spectrophotometrically by metal ion titration.A typical example, obtained in the case of CuCl₂ titration by ligand 3is presented in FIG. 6. In this example, for an M/L ratio increasingfrom 0 to 1, π→π* with transition, centred at 251 nm for the freeligand, is shifted to a lower energy with a concomitant appearance of anabsorption band in the visible region of the spectrum (λ_(max) to 383nm), which is probably the result of an MLCT transition. For greater M/Lratios, no additional change in the UV-visible absorption spectra isobserved. These results correspond to a capacity of the ligand 3 to formone type of Cu(II)complex with an M/L (1/1) stoichiometry.

Similar results were obtained with other ligands in the presence ofCu(II) or Zn(II) and are shown in Table 3.

Preparation of Metal Complexes for Mass Spectrometry Characterisation:

The ligands, dissolved in methanol or dioxane, were metallised in thepresence of one metal ion equivalent for 1 hour at ambient temperaturethen the solvent was evaporated. Cu(AcO)₂ or Zn(AcO)₂ were used for theligands 1 to 11 and CuCl₂ or ZnCl₂ for the other ligands. Controlanalyses, carried out after redissolution of the complexes in theappropriate buffer/organic solvent mixture, showed that UV-visiblespectra of the different complexes thus obtained are the same as thoseobtained in the titration experiments for an identical ligand and metalion stoichiometry.

Cu(II)-1: MS (CID, NH₃) m/z: 364 (LCu(II)-1H), 381 (LCu(II)NH₄-2H).UV/vis [dioxane/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1,v/v)]: λ nm (ε M⁻¹ cm⁻¹)=256 (41,900), 272 (32,200, shoulder), 304(8,800), 338 (5,100), 376 (3,100).

Cu(II)-2: MS (CID, NH₃) m/z: 434 (LCu(II)-1H), 451 (LCu(II)NH₄-2H).Analysis (%) for C₁₉H_(1o)N₂O₂Cl₂Cu: calculated C 52.73; H 2.33; N 6.47;found C 52.52; H 1.64; N 6.48. UV/vis [dioxane/20 mM Tris-HCl pH=7.4containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=256 (38,300), 278(35,900), 310 (10,300), 342 (7,300), 398 (4,000).

Cu(II)-3: MS (CID, NH₃) m/z: 3924Cu(11)-1H), 409 (LCu(II)NH₄-2H).Analysis (%) for C₂₁H₁₆N₂O₂Cu.0.3 C₂H₄O₂: calculated C 63.33; H 4.16; N6.84; found C 63.30; H 3.50; N 6.82. UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=202 (70,800), 254(58,900), 268 (42,400, shoulder), 383 (4,300).

Cu(II)-4: MS (CID, NH₃) m/z: 462 (LCu(II)-1H), 479 (LCu(II)NH₄-2H).Analysis (%) for C₂₁H₁₄N₂O₂Cl₂Cu: calculated C 54.74; H 3.06; N 6.08;found C 54.50; H 2.84; N 5.92. UV/vis [dioxane/20 mM Tris-HCl pH=7.4containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=261 (59,500), 274(46,900, shoulder), 347 (4,700), 409 (5,800).

Cu(II)-5: MS (CID, NH₃) m/z: 400 (CID, NH₃) m/z: UV/vis [CH₃OH/20 mMTris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹cm⁻¹)=205 (64,000), 255 (47,600), 276 (34,400), 415 (2,900).

Cu(II)-6: MS (CID, NH₃) m/z: 378 (LCu(II)-1H), 395 (LCu(II)NH₄-2H).UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]:λ nm (ε M⁻¹ cm⁻¹)=245 (41,100), 306 (27,900), 348 (12,100, shoulder),485 (2,500).

Cu(II)-7: MS (CID, NH₃) m/z: 378 (LCu(II)-1H)395 (LCu(II)NH₄-2H).Analysis (%) for C₂₀H₁₄N₂O₂Cu.0.3 H₂O: calculated C 62.67; H 3.84; N7.31; found C 62.68; H 2.91; N 7.21. UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=202 (57,700), 259(68,000), 268 (46,200, shoulder), 392 (4,900).

Cu(II)-8: MS (CID, NH₃) m/z: 448 (LCu(II)-1H), 465 (LCu(II)NH₄-2H).Analysis (%) for C_(2o)H₁₂N₂O₂Cl₂Cu.0.3 H₂O: calculated C 53.12; H 2.81;N 6.20; found C 53.09; H 2.37; N 6.08. UV/vis [dioxane/20 mM Tris-HClpH=7.4 containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=264(64,700), 276 (46,700), 413 (5,300).

Cu(II)-9: MS (CID, NH₃) m/z: 700 (LCu(II)-1H), 717 (LCu(II)NH₄-2H).Anal. for C₂₀H₁₀N₂O₂Cl₂I₂Cu.2₂H₄O₂): calculated C 35.30; H 1.97; N 3.43;found C 35.46; H 1.20; N 3.83. UV/vis [DMSO/20 mM Tris-HCl pH=7.4containing 150 mM NaCl (8/2, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=(56,000), 340(55,000), 392 (6,200), 420 (5,000).

Cu(II)-10: MS (CID, NH₃) m/z: 406 (LCu(II)-1H), 423 (LCu(II)NH₄-2H).UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]:λ nm (ε M⁻¹ cm⁻¹)=204 (56,000), 260 (71,800), 374 (4,800).

Cu(II)-12-CI: MS (CID, NH₃) m/z: 369 (LCu(II)Cl). UV/vis [DMSO/20 mMTris-HCl pH=7.4 containing 150 mM NaCl (8/2, v/v)]: λ nm (ε M⁻¹cm⁻¹)=287 (40,700), 368 (3,300), 486 (14,100).

Cu(II)-13: MS (electrospray, >0) m/z: 390 (LCu(II)-1H). UV/vis [CH₃OH/20mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹cm⁻¹)=230 (55,700); 303 (11,800), 315 (10,400), 360 (1,100, shoulder).

Cu(II)-14: MS (electrospray, >0) m/z: 405 [LCu(II)].

Cu(II)-16: MS (electrospray, >0) m/z: 423 (LCu(II)-2H). UV/vis [CH₃OH/20mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹cm⁻¹)=254 (34,400), 278 (35,900), 316 (9,700, shoulder), 380 (3,100).

Cu(II)-17: MS (electrospray, >0) m/z: 438 (LCu(II)-1H). UV/vis [CH₃OH/20mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹cm⁻¹)=212 (50,300), 263 (65,300), 275 (47,300, shoulder), 319 (4,500),421 (5,900)

Cu(II)-23: MS (electrospray, >0) m/z: 419 (LCu(II)-1H). UV/vis [CH₃OH/20mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹cm⁻¹)=211 (65,400); 235 (33,800, shoulder), 275 (37,000), 302 (5,900,shoulder), 329 (17,900), 352 (19,000), 366 (20,900).

Cu(II)-24: MS (electrospray, >0) m/z: 361 (LCu(II)-1H).

Zn(II)-1: MS (CID, NH₃) m/z: 365 (LZn(II)-1H), 382 (LZn(II)NH₄-2H).

Zn(II)-2: MS (CID, NH₃) m/z: 433 (LZn(II)-1H(II) 454 (LZn (II)NH₄-2H).

Zn(II)-3: MS (CID, NH₃) m/z: 393 (LZn(II)-1H), 410 (LZn(II)NH₄-2H).UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]:λ nm (ε M⁻¹ cm⁻¹)=202 (78,700), 258 (74,100), 268 (46,700), 378 (4,600).

Zn(II)-4: MS (CID, NH₃) m/z: 463 (LZn(II)-1H), 482 (LZn(II)NH₄-2H).UV/vis [dioxane/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1,v/v)]: λ nm (ε M⁻¹ cm⁻¹)=265 (69,200), 275 (45,700), 346 (5,800), 405(6,100).

Zn(II)-5: MS (CID, NH₃) m/z: 401 (LZn(II)-1H),. UV/vis [CH₃OH/20 mMTris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹cm⁻¹)=205 (43,300), 258 (50,500), 274 (30,900), 404 (3,000).

Zn(II)-6: MS (CID, NH₃) m/z: 379 (LZn(II)-1H), 396 (LZn(II)NH₄-2H).UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]:λ nm (ε M⁻¹ cm⁻¹)=238 (31,100), 298 (26,200), 346 (10,500, shoulder),473 (3,000).

Zn(II)-7: MS (CID, NH₃) m/z: 379 (LZn(II)-1H), 396 (LZn(II)NH₄-2H).UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]:λ nm (ε M⁻¹ cm⁻¹)=202 (55,500), 258 (63,600), 268 (43,400, shoulder),374 (4,000).

Zn(II)-8: MS (CID, NH₃) m/z: 449 (LZn(II)-1H), 466 (LZn(II)NH₄-2H).UV/vis [dioxane/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1,v/v)]: λ nm (ε M⁻¹ cm⁻¹)=264 (57,800), 272 (43,600, shoulder), 390(5,400).

Zn(II)-9: MS (ES-MS, <0) m/z: 735 (LZn(II)HCl). UV/vis [DMSO/20 mMTris-HCl pH=7.4 by silica containing 150 mM NaCl (8/2, v/v)]: λ nm (εM⁻¹ cm⁻¹)=276 (54,200), 340 (5,800), 352 (7,700), 397 (5,100).

Zn(II)-10: (CID, NH₃) m/z: 407 (LZn(II)-1H), 424 (LZn(II)NH₄-2H). UV/vis[CH₃OH/20 mM Tris-HCl pH=7.4; by silica containing 150 mM NaCl (1/1,v/v)]: λ nm (ε M⁻¹ cm⁻¹)=202 (63,600), 260 (65,600), 368 (4,400).

Zn(II)-12-CI: MS (CID, NH₃) m/z: 370 (LZn(II)Cl). UV/vis (CH₃OH): λ nm(ε M⁻¹ cm⁻¹)=288 (31,800), 299 (27,900), 369 (3,400), 490 (13,200).

Zn(II)-13: UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4 by silica containing 150mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=232 (55,400); 300 (9,600), 314(9,200), 364 (700, shoulder).

Zn(II)-14: UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl(1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=236 (43,900), 304 (8,700), 316 (8,000).

Zn(II)-16: MS (electrospray, >0) m/z: 425 (LZn(II)-1H). UV/vis [CH₃OH/20mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹cm⁻¹)=262 (44,700), 276 (22,300, shoulder), 308 (5,900), 390 (2,000).

Zn(II)-17: MS (electrospray, >0) m/z: 439 (LZn(II)-1H). UV/vis [CH₃OH/20mM Tris-HCl pH=7.4 containing 150 mM NaCl (1/1, v/v)]: λ nm (ε M⁻¹cm⁻¹)=202 (66,900); 264 (92,500), 276 (47,100, shoulder), 318 (5,500),398 (6,700).

Zn(II)-18: MS (electrospray, >0) m/z: 394 (LZn(II)-1H). UV/vis [DMSO/20mM Tris-HCl pH=7.4 containing 150 mM NaCl (8/2, v/v)]: λ nm (ε M⁻¹cm⁻¹)=273 (27,400); 309 (23,800), 332 (22,000); 4307 (3,800).

Zn(II)-23: UV/vis [CH₃OH/20 mM Tris-HCl pH=7.4 containing 150 mM NaCl(1/1, v/v)]: λ nm (ε M⁻¹ cm⁻¹)=213 (47,000); 234 (24,800), 274 (25,600),303 (10,900, shoulder), 330 (11,600), 348 (12,300), 363 (13,100).

Estimate of Affinity Constants of Ligands for Metal Ions:

Solutions of ligands to be investigated L_(s), of competing chelatorL_(c) and of metal ion M in the ratio 1/1/1 are analysed by UV-visiblespectrophotometry at 20° C. The concentration of each component is 15μM. UV-visible absorption spectra of L_(s), ML_(s), L_(c) or ML_(c)species and spectrophotometric analyses of competitors are carried outin the presence of a 20 mM Tris-HC buffer containing 150 mM NaCl(pH=7,4) since it is the solvent used in the Aβ₁₋₄₂ resolubilisationexperiments described hereinafter. An organic solvent (CH₃OH, dioxane orDMSO) was added in order to achieve good solubility of all the ligandsand metal complexes in the concentrations used in these experiments.Monitoring has shown that all the ligands and metal complexes examinedyield results corresponding to the Beer-Lambert Law in the experimentalconditions used.

The (L_(c)) metal ion chelators used in the competition experiments wereselected from “The National Institute of Standards and TechnologyStandard Reference Data base 46” NIST (Critically Selected StabilityConstants of Metal Complexes Database, version 4.0, U.S. Department ofCommerce) and L. G. Sillen, A. E. Martell Stability Constants ofMetal-Ion complexes, The Chemical Society London Publication, 1971.

L_(c) competing chelators were selected to provide a range of stabilityconstants for the metal ion M presenting intervals of approximately oneor two log units, as well as to make it possible for each competitionexperiment to quantify one of the L_(s), ML_(s), L_(cc) or ML_(c)species with a UV-vis spectrum wavelength without contaminating thethree other species (FIG. 7). The stability constants K=[ML]/([M][L])selected for the competing chelators are given for 25° C., an ionicstrength of 0.1-0.2 ν and a metal ion to chelator molar ratio of 1/1 inTables 1 and 2. If more than one metal complex can be formed between themetal ion and the chelator, the competing chelator was only selected iflog K of the metal complex thereof having a metal ion to chelator ratioof 1/1 is greater than those of all the other possible complexes.

Log K of a chelator for a metal ion varies with the pH of the solutionas determined by the following equations (C. S. Atwood et al., J.Neurochem. 2000, 75, 1219-1233; A. Ringblom, Complexation in AnalyticalChemistry, 1963, Interscience, New York; G. Schwarznbach et al.,Complexometric Titrations, 1969, Meuthuen, New York):

log K _(app)=log K-log α  (Eq. 1)

where:

α=[H⁺]^(n)/(K _(a1) ×K _(a2) ×K _(a3) × . . . K _(an))+[H⁺]^(n-1)/(K_(a1) ×K _(a2) ×K _(a3) × . . . K _(an-1))+ . . . +[H⁺ ]/K _(a1)+1  (Eq. 2)

K_(a)=10^(×), where x=−pK_(a) of the chelator (K_(a) values are writtenin decreasing order of the pK_(a) values), and n=no. of the pK_(a)value. The log K_(app) for the competing chelators used at pH=7.4 arepresented in Tables 1 and 2.

If L_(S), L_(C) and M are used in a ratio of 1/1/1, and L_(S) forms acomplex MLs with the metal ion and L_(c) forms a complex ML_(c) with themetal ion

$\begin{matrix}{{L_{s} + {M\begin{matrix}\overset{\mspace{25mu} K_{s}\mspace{31mu}}{\rightarrow} \\\leftarrow\end{matrix}{ML}_{s}}}{K_{s} = \frac{\left\lbrack {ML}_{s} \right\rbrack}{\left\lbrack L_{s} \right\rbrack \mspace{14mu}\lbrack M\rbrack}}} & \left( {{Eq}.\mspace{14mu} 3} \right) \\{{L_{c} + {M\begin{matrix}\overset{\mspace{25mu} K_{c\mspace{20mu}}}{\rightarrow} \\\leftarrow\end{matrix}{ML}_{c}}}{K_{c} = \frac{\left\lbrack {ML}_{c} \right\rbrack}{\left\lbrack L_{c} \right\rbrack \mspace{14mu}\lbrack M\rbrack}}} & \left( {{Eq}.\mspace{14mu} 4} \right)\end{matrix}$

K_(c) is the value of K_(app) for the competing chelator L_(C),determined with equations 1 and 2.

It can be deduced therefrom that at equilibrium:

$\begin{matrix}{{\frac{K_{s}}{K_{c}} = \frac{\left\lbrack {ML}_{s} \right\rbrack \mspace{14mu}\left\lbrack L_{c} \right\rbrack}{\left\lbrack {ML}_{c} \right\rbrack \mspace{14mu}\left\lbrack L_{s} \right\rbrack}}{and}} & \left( {{Eq}.\mspace{14mu} 5} \right) \\{K_{s} = {K_{c}\frac{\left\lbrack {ML}_{s} \right\rbrack \mspace{14mu}\left\lbrack L_{c} \right\rbrack}{\left\lbrack {ML}_{c} \right\rbrack \mspace{14mu}\left\lbrack L_{s} \right\rbrack}}} & \left( {{Eq}.\mspace{14mu} 6} \right)\end{matrix}$

The initial concentration C is the same for L_(s), L_(c) and M. If thecomplexes ML_(s) and ML_(c) are observed at the same time on the UV-visspectra for log K_(c)>6, all the metal ion can be considered complexedin the forms of ML_(s) or ML_(c) and at equilibrium:

[ML_(s)]+[ML_(C)]=C=[ML_(s)]+[L_(s)]=[ML_(c)]+[L_(c)]

As the concentration [ML_(s)]=x % of C is measured on the UV-visiblespectra, the concentrations [L_(s)]=(1−x) % of C, [ML_(c)]=(1−x) % of Cand [L_(c)]=x % of C can be deduced therefrom and:

$\begin{matrix}{K_{s} = {K_{c}\frac{x^{2}}{\left( {x - 1} \right)^{2}}}} & \left( {{Eq}.\mspace{14mu} 7} \right)\end{matrix}$

Some experiments were also carried out, in the same solvents, with L_(s)and M in a ratio of 1/1 (15 μM of each) but with different L_(c)stoichiometries. For an initial concentration C=L_(s)=M, theconcentration of the competing ligand [Lc]=y % of C which, atequilibrium, makes it possible to obtain the concentration ratio[ML_(s)]/[L_(s)]=1 and therefore for which the concentrations[ML_(s)]=[L_(s)]=50% of C is deduced from graphs such as those in FIG.8. In these conditions, [ML_(s)]=[ML_(c)]; [ML_(s)]+[L_(c)]=Y, y≧50 and:

$\begin{matrix}{K_{s} = {K_{c}\frac{y - 50}{50}}} & \left( {{Eq}.\mspace{14mu} 8} \right)\end{matrix}$

When log K_(s) 6, these equations are not used since the percentages ofmetal ion which is free in the solution or chelated by the solvent orthe buffer are not negligible.

In the solvent being investigated, therefore, in the case of 12 in thepresence of Zn(II), only the number of ZnCl₂ equivalent has beendetermined, for 15 μM of ligand to be entirely in the form of Zn(II)complex in the solvent being investigated, the ligand being incompetition with the tris buffer and the DMSO for the complexation ofthe metal ion. By comparison with other chelators in the sameconditions: 2,2′-bipyridine (log K_(app)≈5; 250 eq ZnCl₂)<12 (100 eqZnCl₂)<1,10-phenanthroline (log K_(app)=6.3; 50 eq ZnCl₂). Hence anestimation of log K_(s)≈6.

In the same way, in the buffer Tris/CH₃OH (1/1, v/v), the number ofZn(II) equivalent is between 100 and 200 eq for 13, between 500 and 1000eq for 14, between 7.5 and 10 eq for 18, and between 100 and 200 eq for23.

Tables 2 and 3 summarise the values observed during competitions andTable 3 gives the values of affinity constants which have been deducedtherefrom.

Table 4 shows that there is little change in log K_(s) depending on thecomposition of the different media investigated.

TABLE 1 Competition reaction between the ligands (L_(s)), CuCl₂ (M) anda competing ligand (L_(c)) in a ratio of 1/1/1 at 15 15 μM. For eachligand L_(s), the solvents used are those described in Table 3. EDA biPyHIDA Dien EDDA EDTA Trien CTDA Tetren log K₁ 10.5 8.1 11.8 15.9 16.2  18.8 20.1 22.0 22.8 log K₁ app 7.8 8.1 10.5 11.8 13.9   15.9 16.0 17.117.9 log K₂ 9.1 5.5 4.0 5.0 3 100 100 100 — 100 50 (1 eq)   30 15 0 4 —— 100 — 90 40 (0.65 eq) — — — 5 — — — — — 45 — — — 6 — — — — — 75 — — —7 — — — — — 55 (1.1 eq)  — — — 8 — — — — — 40 (0.65 eq) — — — 9 — — —100 — 60 45 (0.75 eq) — 0 10 — — — — — 45 — — — 12 — — — — — 55 — — — 13— — — — 65 25 — — — 17 — — — — — 55 — — — 23 — — — — — 30 — — — Thepercentage of the CuL_(s) species at equilibrium is given. The values inparentheses correspond to the number of L_(c) equivalents, making itpossible to form 50% of CuL_(s) from a mixture of L_(s) (15 μM, 1equivalent) and CuCl₂ (1/1, mol/mol). K₁ is the stability constant forthe ML_(c) species. K₂ is the stability constant for the M(L_(c))₂species.

TABLE 2 Competition reaction between the ligands (L_(s)), ZnCl₂ (M) anda competing ligand (L_(c)) in a ratio of 1/1/1 at 15 μM. Trien NTA EGTAEDTA DTPA log K₁ 11.9 10.5 12.6 16.5 18.2 log K₁ app 7.8 8.0 9.4 13.713.9 log K₂ 3.8 3 100 100 100 30 (0.7 eq) 20 4 — — — 20 — 5 — — — 55 — 6— — — 75 — 7 — — 55 — 8 — — — 30 — 9 100 100 — 65 — 10 — — — 45 — 17 — —— 35 — For each ligand L_(s), the solvents are those described in Table3. The percentage of ZnL_(s) species at equilibrium is given. The valuesin parentheses correspond to the number of L_(c) equivalents making itpossible to form 50% of ZnL_(s) from a mixture of L_(s) (15 μM, 1equivalent) and ZnCl₂ (1/1, mol/mol). K₁ is the stability constant forthe ML_(c) species. K₂ is the stability constant for the M(L_(c))₂species.

TABLE 3 Species formed during titration reactions with CuCl₂ or ZnCl₂and affinity constants of the different ligands for Cu(II) or Zn(II)ions at pH = 7.4. Complex observed by Complex observed by titration withCu^(II) titration with Zn^(II) (observed L/Cu(II) (observed L/Zn(II)Ligand stoichiometry) log KCu^(II) stoichiometry) Log KZn^(II) Solvent 3LCu^(II)(1/1) 15.9 ± 1 ^(a) LZn^(II)(1/1) 13.3 ± 1 ^(a) Buffer/CH₃OH(1/1) 4  Cu^(II)(1/1) 15.4 ± 1 ^(a) LZn^(II)(1/1) 12.5 ± 1 ^(b)Buffer/dioxane ^(c) 5 LCu^(II)(1/1) 15.7 ± 1 ^(b) LZn^(II)(1/1) 13.9 ± 1^(b) Buffer/CH₃OH (1/1) 6 LCu^(II)(1/1) 16.6 ± 1 ^(b) LZn^(II)(1/1) 14.4± 1 ^(b) Buffer/CH₃OH (1/1) 7 LCu^(II)(1/1) 16.0 ± 1 ^(a) LZn^(II)(1/1)13.9 ± 1 ^(b) Buffer/CH₃OH (1/1) 8 LCu^(II)(1/1) 15.4 ± 1 ^(a)LZn^(II)(1/1) 13.0 ± 1 ^(b) Buffer/dioxane ^(c) 9 LCu^(II)(1/1) 15.7 ± 1^(a) LZn^(II)(1/1) 14.2 ± 1 ^(b) Buffer/DMSO (2/8) 10 LCu^(II)(1/1) 15.7± 1 ^(b) LZn^(II)(1/1) 13.5 ± 1 ^(b) Buffer/CH₃OH (1/1) 12 LCu^(II)(1/1)16.0 ± 1 ^(b) LZn^(II)(1/1) ≈6 Buffer/DMSO (2/8) 13 LCu^(II)(1/1) 14.7 ±1 ^(b) — — Buffer/CH₃OH (1/1) 17 LCu^(II)(1/1) 16.0 ± 1 ^(b)LZn^(II)(1/1) 13.2 ± 1 ^(b) Buffer/CH₃OH (1/1) 23 LCu^(II)(1/1) 15.2 ± 1^(b) — — Buffer/CH₃OH (1/1) ^(a) According to Equation 8. ^(b) Accordingto Equation 7. ^(c) Dioxane/20 mM Tris-HCl buffer pH = 7.4 containing150 mM NaCl = 1/1 and 8/2 for the experiments with CuCl₂ and ZnCl₂,respectively.

TABLE 4 Comparison of competition reactions between the ligand 3(L_(s)), CuCl₂ or ZnCl₂ (M) and the competing ligand EDTA (L_(c)) in aratio of 1/1/1 at 15 μM in the different solvents used to determineapparent affinity constants for (K_(s)) metal ions. Metal ion Solvent %MLs K_(s) ^(a) Cu(II) Buffer/CH₃OH (1/1) 50 15.9 Buffer/dioxane (1/1) 4515.7 Buffer/DMSO (2/8) 55 16.1 Zn(II) Buffer/CH₃OH (1/1) 30 13.0Buffer/dioxane (2/8) 33 13.1 Buffer/DMSO (2/8) 35 13.1 CH₃OH 40 13.3 Thepercentage of CuL_(s) species at equilibrium is given. ^(a) According toEquation 7.

Capacity of Compounds to Increase the Solubility of Proteins Involved inNeurodegenerative Diseases:

In the brain of people affected by Alzheimer's disease, the amyloidplaques mainly contain an (Aβ) peptide comprising 39-43 amino acids. Itis produced by digestion of amyloid precursor protein (APP) by β- andγ-secretases. Aβ₁₋₄₀ and Aβ₁₋₄₂ peptides predominate. Pathogenesis isconnected to the accumulation thereof and more particularly to that ofAβ₁₋₄₂, which is the most amyloidogenic and the production of which isamplified by the mutations inducing Alzheimer's' disease or by riskfactors of these disease (M. P. Mattson, Nature, 2004, 430, 631-639; M.Citron, Nature Rev. Neurosci. 2004, 5, 677-685).

Reagents for Experiments Carried Out in the Presence of the Aβ₁₋₄₂Amyloid Peptide:

Before use, the water [of Milli-Q Millipore quality] and all buffersolutions were treated on Chelex-100 resin (Biorad) (5 mg/ml) andfiltered through 0.2 μm filters (Whatman) to remove potential traces ofmetal ions or particles.

CuCl₂, ZnCl₂ or FeCl₃ of puriss p.a. quality are from Fluka.

The β-amyloid peptide Aβ₁₋₄₂ (Aβ₁₋₄₂) was synthesised, purified (to apurity greater than 95%) and characterised by HPLC and MALDI-TOF massspectrometry analysis. Working solutions of the peptide were prepared bysolubilising 1 mg of lyophilised peptide in 500 μl of water and 500 μlof an aqueous NaOH solution pH=12.0, while stirring in a ThermomixerComfort (Eppendorf). The peptide preparations are subsequentlycentrifuged for 10 minutes at 9,000 rpm and the supernatant is used asan “Aβ stock” solution. The concentration of peptide in the “Aβ stock”is determined immediately by colorimetric assay using a Micro BCAProtein Assays kit (Pierce) from standard ranges produced using knownamounts of bovine serum albumin (BSA) then the Aβ₁₋₄₂ peptide solutionis aliquoted and frozen rapidly in liquid nitrogen prior to being storedat −20° C. until being used.

The ligands are used in the form of hydrochlorides except in the case of1 and 16, which are used in their hydrochloride form obtained duringsynthesis, 2,2′-methanediyl-bis(8-hydroxy-2-quinolinium) dichloridedihydrate and2,2′-(methanediyl)-bis(7-methyloxy-8-hydroxy-2-quinolinium) dichloriderespectively. Salts are generated by adding one hydrochloric acidequivalent per nitrogen group equivalent of the ligand dissolved inDMSO. After evaporation of the solvent, these salts are dissolved at thedesired concentration with DMSO and kept at −20° C. until they are used.

Analysis of Aβ₁₋₄₂ Precipitation as a Function of the Cu(II)/PeptideRatio:

The protocol was established from works by: C. S. Atwood et al., J.Neurochem. 2000, 75, 1219-1233. The final concentrations are given.Aβ₁₋₄₂ (5 μm, 500 μl) is set to aggregate in 20 mM Tris-HCl buffercontaining 150 mM NaCl (pH=7.4) for 2 hours at 37° C. while stirring at1,400 rpm in the presence of different CuCl₂ stoichiometries dissolvedin DMSO (50 μl). Samples (final volume=550 μl) are subsequentlycentrifuged for 20 minutes at 9,000 rpm and 500 μl of supernatant aretaken. The tube containing the precipitation pellet thus receives 450 μlof assay buffer/DMSO mixture (91/9, v/v). Then the protein concentrationis determined on the supernatant and the pellet by Micro BCA ProteinAssays (Pierce): each sample receives a volume of colour reagent and isincubated for 1 hour at 60° C. while stirring at 1,400 rpm then theabsorbency at 562 nm is measured. Quantification is carried out on thebasis of standard BSA ranges. The amounts of Aβ₁₋₄₂ actually containedin the pellet and the supernatant are obtained after a correction due tothe presence of a residual portion of the supernatant (50/550 μl) in thepellet-containing fraction. For all experiments, the result of additionof the percentage of Aβ₁₋₄₂ in the supernatant to the percentage ofAβ₁₋₄₂ in the pellet gives values of approximately 100%.

The Cu(II) ion is known to induce the maximum of insoluble aggregatedpeptide-Aβ (C. S. Atwood et al., J. Biol. Chem. 1998, 273, 12817-12826).The Cu(II)/peptide ratio inducing the maximum aggregation under theexperimental conditions used was first determined. FIG. 9 summarises theresults obtained. Without addition of Cu(II), 47% of Aβ₁₋₄₂ isprecipitated. Aggregation increases when the Cu(II)/Aβ₁₋₄₂ ratioincreases to 2.5 Cu(II) through Aβ₁₋₄₂ then stabilises (82% ofaggregated peptide).

Inhibition of the Precipitation of Aβ₁₋₄₂ by the Addition of Ligand:

The protocol was established from works by: C. S. Atwood et al., J.Neurochem. 2000, 75, 1219-1233. The final concentrations are given. 500μl of Aβ₁₋₄₂ (5 μM is set to aggregate in 20 mM Tris-HCl buffercontaining 150 mM NaCl (pH=7.4) for 1 hour at 37° C. while stirring at1,400 rpm in the absence or presence of metal ions: CuCl₂, ZnCl₂ orFeCl₃ (20 μM). Then 50 pi of ligand to be tested (200 μM) dissolved inDMSO are added and the samples are incubated for 1 further hour at 37°C. while stirring at 1,400 rpm. The samples without ligand also receive50 μl of DMSO. The samples (final volume=550 μ) are subsequentlycentrifuged for 20 min at 9,000 rpm, and 500 μl of supernatant areremoved. The tube containing the precipitation pellet then receives 450μl of assay buffer/DMSO mixture (91/9, v/v). Then the proteinconcentration is determined on the supernatant and the pellet by MicroBCA Protein Assays (Pierce): each sample receives a volume of colourreagent and is incubated for 1 hour at 60° C. while stirring at 1,400rpm then the absorbency at 562 nm is measured. Quantification is carriedout on the basis of standard BSA ranges. The amounts of Aβ₁₋₄₂ actuallycontained in the pellet and the supernatant are obtained after acorrection due to the presence of a residual portion of supernatant inthe pellet-containing fraction. In the case of 1, 2, 6, 12, 13, 14, 16,17, 18, 23, of 8-hydroxyquinaldine and 8-aminoquinoline, which haveabsorption at 562 nm under the assay conditions, whites are produced inthe presence of the tested ligand and of the investigated metal ion. Forall experiments, the result of addition of the percentage of Aβ₁₋₄₂ inthe supernatant to the percentage of Aβ₁₋₄₂ in the pellet gives valuesclose to 100%.

The results obtained are summarised in Table 5. They demonstrate thecapacity of the investigated compounds to increase the solubility ofAβ₁₋₄₂ in the presence of metal ions and even, in particular for 1, 2,12, 13, 14, 15, 17, 18, 23 and 24, in the absence of these ions.

An additional test (not presented) has demonstrated that, in thepresence of CuCl₂, the maximum level of peptide precipitation wasachieved after 1 hour of incubation. It can therefore be proposed that,at least in the case of peptide aggregation in the presence of CuCl₂,the ligands (which are added only after 1 hour of incubation) merelyprevent peptide aggregation but can probably act on previously formedaggregates.

TABLE 5 Analysis of solubilisation by the different Aβ₁₋₄₂ ligandsaggregated in the absence or presence of metal ions. without metal CuCl₂ZnCl₂ FeCl₃ % soluble % soluble % soluble % soluble Aβ Aβ Aβ AβUncombined Aβ 55 ± 4 18 ± 2 29 ± 3 47 1 63 ± 4 60 ± 5 63 61 2 66 45 ± 557 58 3 56 47 ± 3 59 60 4 55 30 49 45 5 60 51 ± 1 50 52 6 56 58 ± 3 5451 7 59 35 60 40 8 59 36 58 41 9 36 19 47 38 10 52 42 43 43 11 48 48 4543 12 69 69 ± 2 52 59 13 71 ± 2 55 ± 3 57 66 14 79 ± 3 45 ± 3 57 51 1572 35 23 42 16 53 48 ± 3 50 44 ± 6 17 63 ± 3 38 ± 4 42 ± 4 38 18 66 46 ±3 62 ± 5 49 23 73 60 ± 4 58 ± 4 62 24 64 21 21 38 8-hydroxyquinoline 8570 ± 3 88 80 8-hydroxyquinaldine 69 52 62 51 Clioquinol 63 55 ± 3 37 518-aminoquinoline 66 ± 3 40 67 58 EDTA 41 65 — — Aβ₁₋₄₂ (5 μM) isincubated for 1 hour at 37° C. in 20 mM Tris-HCl buffer (pH = 7.4)containing 150 mM NaCl in the presence or absence of 20 μM (CuCl₂, ZnCl₂or FeCl₂) metal salt then for 1 further hour in the presence of 200 μMligand, then the reaction mixtures are centrifuged. The amounts ofsoluble and precipitated Aβ₁₋₄₂ are determined in the supernatant andthe precipitate respectively using a Micro BCA Protein Assays kit.

Experiments were also carried out with regard to Aβ₁₋₄₂ (5 μM), CuCl₂(12.5 μM) and the ligand (12.5 μM) in order to analyse the effect, onthe aggregation reaction, of minimal stoichiometry (1/1) of ligandrelative to the metal ion with a concentration of this ion leading tomaximum peptide Aβ₁₋₄₂ precipitation. For all experiments, the result ofthe addition of the percentage of Aβ₁₋₄₂ in the supernatant to thepercentage of Aβ₁₋₄₂ in the pellet gives values of approximately 100%.

The results obtained are summarised in FIG. 10.

A stoichiometry of 2.5 equivalents of Cu (II) per peptide was chosenbecause it is the minimum value inducing the maximum aggregation underthe experimental condition employed (FIG. 9). For the controlexperiments with derivatives comprising a single quinoline residue, 5equivalents of ligand were added because complexes of type L₂Cu areconventionally used in these cases.

FIG. 10 summarises the results observed while comparing them with thoseof the previous experiments. Note that the activity of 1, 3, 5, 6, 11and 18 is statistically identical, considering the values with a typicaldeviation ≦5%, whatever the conditions employed, whereas that of theiranalogues comprising a single quinoline residue (8-hydroxyquinoline,Clioquinol and 8-hydroxyquinaldine) decreases when the excess relativeto the peptide or to Cu (II) decreases. For these two experimentalconditions, the values are also close for 13 and 14. Under these twoexperimental conditions, 23 is also more active than its analoguecomprising a single quinoline residue (8-aminoquinoline).

Capacity of the Compounds to Reduce the Oxidising Stress:

It has been proposed that the interactions of Aβ with the Fe and Cu ionscan contribute to the creation of the lesions observed in brainsaffected by Alzheimer's disease. The synthetic peptides Aβ have toxicitywhich correlates with hydrogen peroxide (H₂O₂) production from O₂ via anoxidation-reduction mechanism on the metal ion (M. P. Mattson, Nature2004, 430, 631-639).

Quantitative analysis of the hydrogen peroxide produced by Aβ₁₋₄₂ in thepresence of CuCl₂, reducing agent, air and ligand: The protocol wasestablished from works by: X. Huang et al., J. Biol. Chem. 1999, 274,37111-37116; X. Huang et al., Biochemistry 1999, 38, 7609-7616; C. Opazoet al., J. Biol. Chem. 2002, 277, 40302-40308; K. J. Barnham et al., J.Biol. Chem. 2003, 278, 42959-42965; G. D. Ciccotosto et al., J. Biol.Chem. 2004, 279, 42528-42534.

The final concentrations are given. The reactions were carried out inthe dark in mM sodium phosphate buffer (pH=7.4). Aβ₁₋₄₂ (0.2 μM) andCuCl₂ (0.4 μM) were pre-incubated for 1 hour at 37° C. while stirring at1,400 rpm in 375 μl of buffer. Then 2 μl of a solution of ligand to beinvestigated (0.2; 0.4 or 0.8 μM) in DMSO were added. After incubationfor a further hour, 2 μl of an aqueous sodium ascorbate solution (10 μM)were added and incubation was continued for 5 min while stirring. Theamount of H₂O₂ produced is then quantified using an Amplex Red H₂O₂/HRPAssay Kit (Molecular Probes) while adding a volume of assay reagent tothe samples, then incubating them for 1 hour at 37° C. while stirring at500 rpm. H₂O₂ is then detected by spectrophotometry at 563 nm.Quantification is carried out on the basis of standard curves obtainedwith known amounts of H₂O₂. The results obtained are summarised in Table6 and FIG. 11.

Experiments were also carried out in the presence of a known amount ofH₂O₂, added just before or just after the addition of sodium ascorbate,in order to investigate the stability of H₂O₂ under the experimentalconditions employed. The results obtained are summarised in Table 7.

Other experiments were carried out in the presence of differentconcentrations of peptide Aβ₁₋₄₂ (0.2 to 0.53 μM) and CuCl₂ (0.4 μM),with or without addition of ligand (0.4 μM) and of known amounts ofH₂O₂, in order to investigate the influence of the stoichiometryAβ₁₋₄₂/Cu on the production of H₂O₂ by the investigated systems. Theresults obtained are summarised in FIG. 11.

The peptide A6 can chelate various stoichiometries of Cu(II) and thusform different types of complexes. All these species can have differentcapacities to produce H₂O₂ in the presence of dioxygen and reducingagent. Titration of the amount of H₂O₂ produced by 0.4 μM of Cu(II) as afunction of the concentration of Aβ₁₋₄₂ causes this phenomenon to appear(FIG. 11). The amount of H₂O₂ produced increases when the Cu/Aβ₁₋₄₂ratio increases. The same experiments were carried out in the presenceof 1 equivalent of ligand 3 or 7 (II) per Cu(II). The two compoundsvirtually inhibit H₂O₂ production, whatever the tested Cu/Aβ₁₋₄₂ ratio.

Table 6 shows that the various quinoline derivatives tested inhibit theproduction of H₂O₂, whatever the experimental conditions employed.

TABLE 6 Comparison of inhibition by the various ligands (0.4 μM) of theproduction of H₂O₂ effected by Aβ₁₋₄₂ (0.2 and 0.5 μM) in the presenceof CuCl₂0.4 μM), ascorbate (10 μM) and air. Ligand 1 eq/Cu(II) without0.2 μM Aβ₁₋₄₂ 0.5 μM Aβ₁₋₄₂ (when not specified) Aβ₁₋₄₂ Cu/Aβ = 2 Cu/Aβ= 0.75 without ligand 2.91 ± 0.22 2.83 ± 0.19 1.08  1 0.54 0.75 ± 0.110.76  2 0.56 0.80 ± 0.23 0.61  3 0.5 eq/Cu(II) 2.12 0.94 — 1 eq/Cu(II)0.84 0.71 ± 0.02 0.55 1.5 eq/Cu(II) — 0.49 —  4 0.12 0.37 ± 0.09 0.35  50.39 0.55 ± 0.08 —  6 0.82 0.86 ± 0.11 —  7 0.75 0.89 ± 0.07 0.68  80.66 0.89 ± 0.09 0.64  9 0.66 0.82 ± 0.08 0.82 12 0.40 0.47 ± 0.09 — 130.89 2.10 0.70 14 0.74 1.99 0.78 15 — 1.02 — 16 — 0.70 — 17 — 0.69 — 180.47 0.47 0.45 23 0.65 0.69 0.49 24 0.49 0.62 0.47 8-hydroxyquinoline 1eq/Cu(II) 2.02 0.69 0.75 2 eq/Cu(II) 0.62 0.71 ± 0.05 0.62 Clioquinol 1eq/Cu(II) 2.07 0.89 ± 0.08 0.64 2 eq/Cu(II) 0.54 0.78 ± 0.06 0.57without ligand and 0.49 ± 0.19 0.69 0.51 without Cu(II) without ligand,without 0   0.06 — ascorbate and without Cu(II)The figures in the tables correspond to the amount of H₂O₂ (expressed innanomoles) added using an Amplex Red H₂O₂/HRP Assay kit.

In a control experiment carried out with only the ligand without amyloidpeptide β₁₋₄₂ and without Cu, determination of the production of H₂O₂due to traces of metals present in the investigated medium is alwaysless than 0.49±19 nanomoles of H₂O₂.

Table 7 shows that, under the experimental conditions employed, theligands can be divided into two categories: (i) those which inhibit theproduction of H₂O₂ but do not degrade it (all of the added H₂O₂ is foundagain); (ii) those for which the decrease in H₂O₂ is associated with itsdegradation (as in the case of 12 where none of the added H₂O₂ is foundagain).

TABLE 7 Analysis of the stability of H₂O₂ during experiments to inhibit,via the ligands, production of H₂O₂ effected by Aβ₁₋₄₂ (0.2 or 0.4 μM)in the presence of CuCl₂ (0.4 μM), ascorbate (10 μM) and air. Aβ₁₋₄₂Cu(II) ascorbate ligand 0.2 μM ^(a) 0.4 μM 10 μM 0.4 μM ^(a) H₂O₂ H₂O₂0.075 0.15 3.8 0.15 added assayed nanomole nanomole nanomoles nanomolenanomoles nanomoles − − + − − 0.49 ± 0.19 − − + − 3.0 3.2 (3.5) − + + −− 2.91 ± 0.22 − + + − 1.5 4.0 (4.4) − + + −   1.5 ^(b) 3.6 (4.4) + + + −− 2.83 ± 0.19 + + + − 1.5 4.2 (4.3) + + + −   1.5 ^(b) 4.2 (4.3) 0.4μM + + − − 1.6 0.4 μM + + − 1.5 3.0 (3.1) 0.4 μM + + −   1.5 ^(b) 3.0(3.1) − + − 3 3.0 3.1 − + + 3 −  0.84 − + + 3 3.0 3.8 (3.8) + + + 3 −0.71 ± 0.02 + + + 3 3.0 3.7 (3.7) + + + 3   3.0 ^(b) 3.8 (3.7) + + + 4 −0.37 ± 0.09 + + + 4 3.0 3.3 (3.4) + + + 5 − 0.55 ± 0.08 + + + 5 3.0 3.4(3.5) + + + 6 − 0.87 ± 0.11 + + + 6 3.0 3.6 (3.9) + + + 12 − 0.47 ±0.09 + + + 12 3.0 1.7 (3.4) + + + 14 − 1.99 ± 0.11 + + + 14   3.0 ^(b)4.9 (5.0) − + + 18 −  0.47 − + + 18   3.0 ^(b) 3.5 (3.5) Analysis isachieved by comparing the results obtained with or without addition of aknown amount of H₂O₂ in the reaction medium just after the addition ofascorbate, if not specified by b). The theoretical value of H₂O₂ isgiven in parentheses if there is no degradation. It corresponds to theaddition of the number of nanomoles of H₂O₂ added to those produced in areaction carried out under the same experimental conditions but withoutaddition of H₂O₂. H₂O₂ is assayed using an Amplex Red H₂O₂/HRP Assaykit. ^(a) When not specified ^(b) H₂O₂ added just before the ascorbate.

Modulation of Hydrophobicity:

Determination of log D_(7.4): The method is adapted from Z.-P Zhuang etal., J. Med. Chem., 2001, 44, 1905-1914. The ligand (2.0 mg) isdissolved in 2 ml of 1-octanol then 2 ml of 20 mM Tris-HCl buffer,pH=7.4 containing 150 mM NaCl are added. After mixing in a vortex for 3min at ambient temperature, followed by centrifugation for 5 min at9,000 rpm, the concentration of the ligand in each phase is determinedby UV-visible spectrophotometry. The 1-octanol fractions are thusredivided until reproducible values of coefficient of division ofobtained. This coefficient is expressed as the decimal logarithm of[(the concentration of ligand contained in the 1-octanol phase)/(theconcentration of ligand contained in the buffered aqueous phase)]=logD_(7.4). Measurements were taken three times.

Table 8 summarises the results obtained.

The value of log D_(7.4) reflects the hydrophobicity and therefore thelipophilicity of the compounds, which is one of the parameters used(with others such as the molecular weight) to estimate the possibilitiesof biodistribution of the molecules (H. van de Waterbeemd et al., NatureRev. Drug Discovery 2003, 2, 192-204).

For identical substitutions of the aromatic macrocycles, the derivativescomprising a single quinoline residue are more hydrophilic than thosecomprising a plurality thereof. The hydrophobicity can be modulated bythe length of the arm joining the quinoline residues (compare 7 and 10),by the nature of said arm (compare 7 and 18) and by the substitution ofthe hydrogens of the rings (compare respectively: 1 and 2; 3 and 4; 7,8, 9 and 17) or joining arms (compare1, 3, 5 and 6 by different groups.

TABLE 8 Value of the decimal logarithm of the coefficient of dividion ofthe ligands between 1-octanol (hydrophobic phase) and 20 mM Tris-HClbuffer containing 150 mM NaCl (pH = 7.4) (hydrophilic phase) (1/1, v/v).Ligand PM log D_(7.4) 1 301 3.3 ± 0.1 2 370 3.5 ± 0.1 3 330 4.4 ± 0.1 4398 4.9 ± 0.1 5 338 3.8 ± 0.1 6 316 3.9 ± 0.1 7 316 3.5 ± 0.1 8 384 4.2± 0.1 9 636 5.6 ± 0.5 10 344 3.8 ± 0.1 11 474 3.7 ± 0.1 12 271 3.5 ± 0.113 328 2.7 ± 0.1 14 342 1.8 ± 0.1 15 272 2.0 ± 0.1 17 376 3.5 ± 0.1 18331 3.0 ± 0.1 23 357 2.5 ± 0.1 24 299 2.6 ± 0.1 8-hydroxyquinoline 1452.1 ± 0.1 8-hydroxyquinaldine 159 2.4 ± 0.1 Clioquinol 305 3.8 ± 0.18-aminoquinoline 144 1.9 ± 0.1

Analysis of Potential Genotoxicity:

AMES test: The method is adapted from D. M. Maron and B. N. Ames, Mutat.Res. 1983, 113, 173-215; D. E. Levin et al., Mutat. Res. 1982, 94,315-330; D. E. Levin et al. Proc. Natl. USA 1982, 79, 7445-7449.

Two test lines (TA98 and TA100) of mutant Salmonella tiphimurium (His⁻)were used on account of their inability to synthesise histidine and theconfirmation of the characteristics of these lines by genetic labelexperiments. The test involves evaluating the potential of the testedmolecules to induce mutation which is reverse to the histidine locus ofthese lines. These two lines were provided by Dr. Bruce N. Ames(University of California, Berkeley, USA). They are resistant toAmpicillin and sensitive to Tetracycline. They are not mutant towardrfa, UvγV and UvγA. The line TA98 (his D3052) contains a mutation ofreading phase (GC) whereas the line TA100 (his G46) contains asubstitution of base pair (GC). The number of spontaneous revertants is37±6 and 166±15 colonies per plate in the case of TA98 and TA100respectively.

The compounds to be tested were dissolved in 100% of DMSO (the solvent)and diluted logarithmically (by a factor of 10) so as to obtain 4 testconcentrations of 30,000; 3,000; 300 and 30 μg/ml. Each series of 0.1 mlof stock solution to be tested, 0.1 ml of test line and of culturemedium with or without 0.5 ml of enzymatic homogenate (S9) of rat livermicrosome were mixed with 2 ml of molten agarose (containing 0.5 mM ofhistidine and 0.5 mM of biotin). This mixture was placed on the surfaceof a plate of minimal agarose glucose medium (30 ml for each Petri dish)so as to obtain final concentrations of compound to be tested of 3,000;300; 30 and 3 μγ/plate. The plates were then incubated at 37° C. for 48hours. The cultures were treated or not treated in the presence of anexogenous metabolic activation by the addition of 0.5 ml of mixture S9containing 8 mM MgCl₂, 33 mM KCl, 4 mM NADP, 5 mM glucose-6-phosphate,100 mM NaH₂PO₄ (pH=7.4) and 4% (v/v) of enzymatic homogenate of ratliver microsome induced by Acrolor 1254 (S9). The revertant colonies ofthe test lines were counted using a colony counter (Sigma). The resultswere considered as significant only if the values obtained for thesolvent alone and the reference compounds were in a previouslyestablished range. A number of colonies ≧3 times the number of coloniesobserved for the solvent alone is deemed to be significantly mutagenic.A compound inducing a number of colonies <50% of cells obtained for thesolvent alone was deemed to be toxic for the bacteria tested. All theexperiments were carried out in triplicate.

The obtaining of expected results with these lines for 4-NPC, sodiumazide, 2-anthramine and 2-aminofluorene confirmed the high quality ofthe investigation.

The results obtained are summarised in Table 9.

TABLE 9 Results of the Ames test for mutagenicity of Salmonella on theTA98 and TA100 strains of salmonella in the absence or presence ofenzymatic homogenate (S9) of rat liver microsome. TA98 TA100 CompoundAddition Mutagenic Mutagenic (value per plate) of S9 effect Cytotoxicityeffect Cytotoxicity DMSO (solvent) no >100 μl >100 μl >100 μl >100 μlyes >100 μl >100 μl >100 μl >100 μl Clioquinol no — 300 μg — 30 μg yes —300 μg — 30 μg 3 no >3000 μg >3000 μg >3000 μg >3000 μg yes >3000μg >3000 μg >3000 μg >3000 μg 5 no >3000 μg >3000 μg — 300 μg yes >3000μg >3000 μg >3000 μg >3000 μg 12  no >3000 μg >3000 μg >3000 μg >3000 μgyes >3000 μg >3000 μg >3000 μg >3000 μg

A bactericidal effect of Clioquinol is observed on the two lines. Nomutagenic effect was observed on the polyquinoline compounds tested,even in the case of the strongest doses investigated. No bactericidaleffect was observed for these compounds, even in the case of thestrongest doses tested, except for compound 5 as from 300 μg/plate, onthe TA100 line in the absence of S9.

1. A method for chelating metal ion and/or dissolving amyloidaggregates, comprising chelating metal ions and/or dissolving amyloidaggregates with a compound of formula (I):

wherein in formula (I): X represents an -NRR′ group and Y represents agroup of formula:

in which X′ represents an -NRR′ group and Z represents a group offormula -(Alk)_(n)-(A′)-(Alk′)_(n′), where: n, n′ are the same ordifferent and independently represent 0 or 1, A′ is —NR—, Alk, Alk′ arethe same or different and independently represent an -alkyl- group, Rand R′ are the same or different and independently represent a hydrogenatom or a cycloalkyl or alkyl group, optionally substituted by one ormore groups selected from OR, NRR′, Hal, —CN, —CF₃, S(O)_(p)R, COOR,OCOOR, CONRR′ and NRCOOR′, heteroaryl;R1=R2=R3=R4=R5=R1′=R2′=R3′=R4′=R5′=H, k is 1, p is 0, 1 or 2; as well asthe pharmaceutically acceptable stereoisomers or mixtures, tautomericforms, hydrates, solvates, salts, free forms and esters thereof.
 2. Themethod according to claim 1, wherein the compounds are selected from thegroup consisting of: 2,2′-(iminodimethanediyl)di(N-boc-8-quinolineamine), 2,2′-(iminodimethanediyl)di(8-quinoline amine),2,2′-[(butylimino)dimethanediyl]di(N-boc-8-quinoline amine),2,2′-[(butylimino)dimethanediyl]di(8-quinoline amine),N-butyl-2,2′-imino-bis(8-quinoline amine), andN-butyl-2,2′-imino-bis(8-quinoline amine).
 3. The method according toclaim 1, wherein in formula (I) X represents NRR′ and Y represents agroup of formula (IY), in which X′ represents NRR′ and Z representsAlk-NR″-Alk, where Alk represents a linear or branched alkyl groupoptionally substituted by one or more halogen atoms; or X representsNRR′ and Y represents a group of formula (IY), in which X′ representsNRR′ and Z represents NR″; k=1 and R1=R2=R3=R4=R5=R1′=R2′=R3′=R4′=R5′=H.4. The method according to claim 1, wherein said metals are selectedfrom copper.
 5. A method for treating and/or preventing diseases thataffect the central nervous system, chosen from Alzheimer's disease,Parkinson's disease, Huntington's disease, amyotrophic lateralsclerosis, comprising administering to a patient in need thereof aneffective amount of a compounds of formula (I)

wherein in formula (I): X represents an —NRR′ group and Y represents agroup of formula:

in which X′ represents an —NRR′ group and Z represents a group offormula -(Alk)_(n)-(A′)-(Alk′)_(n′), where n, n′ are the same ordifferent and independently represent 0 or 1, A′ is —NR—, Alk, Alk′ arethe same or different and independently represent an -alkyl- group, Rand R′ are the same or different and independently represent a hydrogenatom or a cycloalkyl or alkyl group, optionally substituted by one ormore groups selected from OR, NRR′, Hal, —CN, —CF₃, S(O)_(p)R, COOR,OCOOR, CONRR′ and NRCOOR′; heteroaryl;R1=R2=R3=R4=R5=R1′=R2′=R3′=R4′=R5′=H, k is 1, p is 0, 1 or 2; as well asthe pharmaceutically acceptable stereoisomers or mixtures, tautomericforms, hydrates, solvates, salts, free forms and esters thereof.
 6. Themethod according to claim 5, wherein in formula (I) X represents NRR′and Y represents a group of formula (IY), in which X′ represents NRR′and Z represents Alk-NR″-Alk, where Alk represents a linear or branchedalkyl group optionally substituted by one or more halogen atoms; or Xrepresents NRR′ and Y represents a group of formula (IY), in which X′represents NRR′ and Z represents NR″; k=1 andR1=R2=R3=R4=R5=R1′=R2′=R3′=R4′=R5′=H.
 7. The method according to claim5, wherein the compounds are selected from the group consisting of:2,2′-(iminodimethanediyl)di(N-boc-8-quinoline amine),2,2′-(iminodimethanediyl)di(8-quinoline amine),2,2′-[(butylimino)dimethanediyl]di(N-boc-8-quinoline amine),2,2′-[(butylimino)dimethanediyl]di(8-quinoline amine),N-butyl-2,2′-imino-bis(8-quinoline amine), andN-butyl-2,2′-imino-bis(8-quinoline amine).